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* Update copyright dates with scripts/update-copyrightsPaul Eggert2021-01-025-5/+5
| | | | | | | | | | | | | | | | I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 6694 files FOO. I then removed trailing white space from benchtests/bench-pthread-locks.c and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this diagnostic from Savannah: remote: *** pre-commit check failed ... remote: *** error: lines with trailing whitespace found remote: error: hook declined to update refs/heads/master
* nptl: Move stack list variables into _rtld_globalFlorian Weimer2020-11-161-2/+0
| | | | | | | | | Now __thread_gscope_wait (the function behind THREAD_GSCOPE_WAIT, formerly __wait_lookup_done) can be implemented directly in ld.so, eliminating the unprotected GL (dl_wait_lookup_done) function pointer. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* aarch64: enforce >=64K guard size [BZ #26691]Szabolcs Nagy2020-10-021-0/+3
| | | | | | | | | | | | | | | | | | | | | | | There are several compiler implementations that allow large stack allocations to jump over the guard page at the end of the stack and corrupt memory beyond that. See CVE-2017-1000364. Compilers can emit code to probe the stack such that the guard page cannot be skipped, but on aarch64 the probe interval is 64K by default instead of the minimum supported page size (4K). This patch enforces at least 64K guard on aarch64 unless the guard is disabled by setting its size to 0. For backward compatibility reasons the increased guard is not reported, so it is only observable by exhausting the address space or parsing /proc/self/maps on linux. On other targets the patch has no effect. If the stack probe interval is larger than a page size on a target then ARCH_MIN_GUARD_SIZE can be defined to get large enough stack guard on libc allocated stacks. The patch does not affect threads with user allocated stacks. Fixes bug 26691.
* linux: Remove INTERNAL_SYSCALL_DECLAdhemerval Zanella2020-02-141-3/+2
| | | | | | | | | | | With all Linux ABIs using the expected Linux kABI to indicate syscalls errors, the INTERNAL_SYSCALL_DECL is an empty declaration on all ports. This patch removes the 'err' argument on INTERNAL_SYSCALL* macro and remove the INTERNAL_SYSCALL_DECL usage. Checked with a build against all affected ABIs.
* Update copyright dates with scripts/update-copyrights.Joseph Myers2020-01-015-5/+5
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* nptl: Add default pthread-offsets.hAdhemerval Zanella2019-11-261-3/+0
| | | | | | | | | | This patch adds a default pthread-offsets.h based on default thread definitions from struct_mutex.h and struct_rwlock.h. The idea is to simplify new ports inclusion. Checked with a build on affected abis. Change-Id: I7785a9581e651feb80d1413b9e03b5ac0452668a
* nptl: Add struct_rwlock.hAdhemerval Zanella2019-11-261-17/+0
| | | | | | | | | | | | | | | | | | | | | | | | This patch adds a new generic __pthread_rwlock_arch_t definition meant to be used by new ports. Its layout mimics the current usage on some 64 bits ports and it allows some ports to use the generic definition. The arch __pthread_rwlock_arch_t definition is moved from pthreadtypes-arch.h to another arch-specific header (struct_rwlock.h). Also the static intialization macro for pthread_rwlock_t is set to use an arch defined on (__PTHREAD_RWLOCK_INITIALIZER) which simplifies its implementation. The default pthread_rwlock_t layout differs from current ports with: 1. Internal layout is the same for 32 bits and 64 bits. 2. Internal flag is an unsigned short so it should not required additional padding to align for word boundary (if it is the case for the ABI). Checked with a build on affected abis. Change-Id: I776a6a986c23199929d28a3dcd30272db21cd1d0
* nptl: Add struct_mutex.hAdhemerval Zanella2019-11-261-7/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current way of defining the common mutex definition for POSIX and C11 on pthreadtypes-arch.h (added by commit 06be6368da16104be5) is not really the best options for newer ports. It requires define some misleading flags that should be always defined as 0 (__PTHREAD_COMPAT_PADDING_MID and __PTHREAD_COMPAT_PADDING_END), it exposes options used solely for linuxthreads compat mode (__PTHREAD_MUTEX_USE_UNION and __PTHREAD_MUTEX_NUSERS_AFTER_KIND), and requires newer ports to explicit define them (adding more boilerplate code). This patch adds a new default __pthread_mutex_s definition meant to be used by newer ports. Its layout mimics the current usage on both 32 and 64 bits ports and it allows most ports to use the generic definition. Only ports that use some arch-specific definition (such as hardware lock-elision or linuxthreads compat) requires specific headers. For 32 bit, the generic definitions mimic the other 32-bit ports of using an union to define the fields uses on adaptive and robust mutexes (thus not allowing both usage at same time) and by using a single linked-list for robust mutexes. Both decisions seemed to follow what recent ports have done and make the resulting pthread_mutex_t/mtx_t object smaller. Also the static intialization macro for pthread_mutex_t is set to use a macro __PTHREAD_MUTEX_INITIALIZER where the architecture can redefine in its struct_mutex.h if it requires additional fields to be initialized. Checked with a build on affected abis. Change-Id: I30a22c3e3497805fd6e52994c5925897cffcfe13
* nptl: Remove rwlock elision definitionsAdhemerval Zanella2019-11-261-2/+0
| | | | | | | | | | The new rwlock implementation added by cc25c8b4c1196 (2.25) removed support for lock-elision. This patch removes remaining the arch-specific unused definitions. Checked with a build against all affected ABIs. Change-Id: I5dec8af50e3cd56d7351c52ceff4aa3771b53cd6
* nptl: Add tests for internal pthread_rwlock_t offsetsAdhemerval Zanella2019-11-261-0/+2
| | | | | | | | | | | | | This patch new build tests to check for internal fields offsets for internal pthread_rwlock_t definition. Althoug the '__data.__flags' field layout should be preserved due static initializators, the patch also adds tests for the futexes that may be used in a shared memory (although using different libc version in such scenario is not really supported). Checked with a build against all affected ABIs. Change-Id: Iccc103d557de13d17e4a3f59a0cad2f4a640c148
* nptl: Cleanup mutex internal offset testsAdhemerval Zanella2019-11-261-4/+0
| | | | | | | | | | | | | The offsets of pthread_mutex_t __data.__nusers, __data.__spins, __data.elision, __data.list are not required to be constant over the releases. Only the __data.__kind is used for static initializers. This patch also adds an additional size check for __data.__kind. Checked with a build against affected ABIs. Change-Id: I7a4e48cc91b4c4ada57e9a5d1b151fb702bfaa9f
* Split up endian.h to minimize exposure of BYTE_ORDER.Alistair Francis2019-10-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With only two exceptions (sys/types.h and sys/param.h, both of which historically might have defined BYTE_ORDER) the public headers that include <endian.h> only want to be able to test __BYTE_ORDER against __*_ENDIAN. This patch creates a new bits/endian.h that can be included by any header that wants to be able to test __BYTE_ORDER and/or __FLOAT_WORD_ORDER against the __*_ENDIAN constants, or needs __LONG_LONG_PAIR. It only defines macros in the implementation namespace. The existing bits/endian.h (which could not be included independently of endian.h, and only defines __BYTE_ORDER and maybe __FLOAT_WORD_ORDER) is renamed to bits/endianness.h. I also took the opportunity to canonicalize the form of this header, which we are stuck with having one copy of per architecture. Since they are so short, this means git doesn’t understand that they were renamed from existing headers, sigh. endian.h itself is a nonstandard header and its only remaining use from a standard header is guarded by __USE_MISC, so I dropped the __USE_MISC conditionals from around all of the public-namespace things it defines. (This means, an application that requests strict library conformance but includes endian.h will still see the definition of BYTE_ORDER.) A few changes to specific bits/endian(ness).h variants deserve mention: - sysdeps/unix/sysv/linux/ia64/bits/endian.h is moved to sysdeps/ia64/bits/endianness.h. If I remember correctly, ia64 did have selectable endianness, but we have assembly code in sysdeps/ia64 that assumes it’s little-endian, so there is no reason to treat the ia64 endianness.h as linux-specific. - The C-SKY port does not fully support big-endian mode, the compile will error out if __CSKYBE__ is defined. - The PowerPC port had extra logic in its bits/endian.h to detect a broken compiler, which strikes me as unnecessary, so I removed it. - The only files that defined __FLOAT_WORD_ORDER always defined it to the same value as __BYTE_ORDER, so I removed those definitions. The SH bits/endian(ness).h had comments inconsistent with the actual setting of __FLOAT_WORD_ORDER, which I also removed. - I *removed* copyright boilerplate from the few bits/endian(ness).h headers that had it; these files record a single fact in a fashion dictated by an external spec, so I do not think they are copyrightable. As long as I was changing every copy of ieee754.h in the tree, I noticed that only the MIPS variant includes float.h, because it uses LDBL_MANT_DIG to decide among three different versions of ieee854_long_double. This patch makes it not include float.h when GCC’s intrinsic __LDBL_MANT_DIG__ is available. * string/endian.h: Unconditionally define LITTLE_ENDIAN, BIG_ENDIAN, PDP_ENDIAN, and BYTE_ORDER. Condition byteswapping macros only on !__ASSEMBLER__. Move the definitions of __BIG_ENDIAN, __LITTLE_ENDIAN, __PDP_ENDIAN, __FLOAT_WORD_ORDER, and __LONG_LONG_PAIR to... * string/bits/endian.h: ...this new file, which includes the renamed header bits/endianness.h for the definition of __BYTE_ORDER and possibly __FLOAT_WORD_ORDER. * string/Makefile: Install bits/endianness.h. * include/bits/endian.h: New wrapper. * bits/endian.h: Rename to bits/endianness.h. Add multiple-include guard. Rewrite the comment explaining what the machine-specific variants of this file should do. * sysdeps/unix/sysv/linux/ia64/bits/endian.h: Move to sysdeps/ia64. * sysdeps/aarch64/bits/endian.h * sysdeps/alpha/bits/endian.h * sysdeps/arm/bits/endian.h * sysdeps/csky/bits/endian.h * sysdeps/hppa/bits/endian.h * sysdeps/ia64/bits/endian.h * sysdeps/m68k/bits/endian.h * sysdeps/microblaze/bits/endian.h * sysdeps/mips/bits/endian.h * sysdeps/nios2/bits/endian.h * sysdeps/powerpc/bits/endian.h * sysdeps/riscv/bits/endian.h * sysdeps/s390/bits/endian.h * sysdeps/sh/bits/endian.h * sysdeps/sparc/bits/endian.h * sysdeps/x86/bits/endian.h: Rename to endianness.h; canonicalize form of file; remove redundant definitions of __FLOAT_WORD_ORDER. * sysdeps/powerpc/bits/endianness.h: Remove logic to check for broken compilers. * ctype/ctype.h * sysdeps/aarch64/nptl/bits/pthreadtypes-arch.h * sysdeps/arm/nptl/bits/pthreadtypes-arch.h * sysdeps/csky/nptl/bits/pthreadtypes-arch.h * sysdeps/ia64/ieee754.h * sysdeps/ieee754/ieee754.h * sysdeps/ieee754/ldbl-128/ieee754.h * sysdeps/ieee754/ldbl-128ibm/ieee754.h * sysdeps/m68k/nptl/bits/pthreadtypes-arch.h * sysdeps/microblaze/nptl/bits/pthreadtypes-arch.h * sysdeps/mips/ieee754/ieee754.h * sysdeps/mips/nptl/bits/pthreadtypes-arch.h * sysdeps/nios2/nptl/bits/pthreadtypes-arch.h * sysdeps/nptl/pthread.h * sysdeps/riscv/nptl/bits/pthreadtypes-arch.h * sysdeps/sh/nptl/bits/pthreadtypes-arch.h * sysdeps/sparc/sparc32/ieee754.h * sysdeps/unix/sysv/linux/generic/bits/stat.h * sysdeps/unix/sysv/linux/generic/bits/statfs.h * sysdeps/unix/sysv/linux/sys/acct.h * wctype/bits/wctype-wchar.h: Include bits/endian.h, not endian.h. * sysdeps/unix/sysv/linux/hppa/pthread.h: Don’t include endian.h. * sysdeps/mips/ieee754/ieee754.h: Use __LDBL_MANT_DIG__ in ifdefs, instead of LDBL_MANT_DIG. Only include float.h when __LDBL_MANT_DIG__ is not predefined, in which case define __LDBL_MANT_DIG__ to equal LDBL_MANT_DIG.
* Prefer https to http for gnu.org and fsf.org URLsPaul Eggert2019-09-075-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Also, change sources.redhat.com to sourceware.org. This patch was automatically generated by running the following shell script, which uses GNU sed, and which avoids modifying files imported from upstream: sed -ri ' s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g ' \ $(find $(git ls-files) -prune -type f \ ! -name '*.po' \ ! -name 'ChangeLog*' \ ! -path COPYING ! -path COPYING.LIB \ ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \ ! -path manual/texinfo.tex ! -path scripts/config.guess \ ! -path scripts/config.sub ! -path scripts/install-sh \ ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \ ! -path INSTALL ! -path locale/programs/charmap-kw.h \ ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \ ! '(' -name configure \ -execdir test -f configure.ac -o -f configure.in ';' ')' \ ! '(' -name preconfigure \ -execdir test -f preconfigure.ac ';' ')' \ -print) and then by running 'make dist-prepare' to regenerate files built from the altered files, and then executing the following to cleanup: chmod a+x sysdeps/unix/sysv/linux/riscv/configure # Omit irrelevant whitespace and comment-only changes, # perhaps from a slightly-different Autoconf version. git checkout -f \ sysdeps/csky/configure \ sysdeps/hppa/configure \ sysdeps/riscv/configure \ sysdeps/unix/sysv/linux/csky/configure # Omit changes that caused a pre-commit check to fail like this: # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines git checkout -f \ sysdeps/powerpc/powerpc64/ppc-mcount.S \ sysdeps/unix/sysv/linux/s390/s390-64/syscall.S # Omit change that caused a pre-commit check to fail like this: # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
* Update copyright dates with scripts/update-copyrights.Joseph Myers2019-01-015-5/+5
| | | | | | | * 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.
* hurd: add gscope supportSamuel Thibault2018-03-111-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | * elf/dl-support.c [!THREAD_GSCOPE_IN_TCB] (_dl_thread_gscope_count): Define variable. * sysdeps/generic/ldsodefs.h [!THREAD_GSCOPE_IN_TCB] (struct rtld_global): Add _dl_thread_gscope_count member. * sysdeps/mach/hurd/tls.h: Include <atomic.h>. [!defined __ASSEMBLER__] (THREAD_GSCOPE_GLOBAL, THREAD_GSCOPE_SET_FLAG, THREAD_GSCOPE_RESET_FLAG, THREAD_GSCOPE_WAIT): Define macros. * sysdeps/generic/tls.h: Document THREAD_GSCOPE_IN_TCB. * sysdeps/aarch64/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/alpha/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/arm/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/hppa/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/i386/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/ia64/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/m68k/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/microblaze/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/mips/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/nios2/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/powerpc/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/riscv/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/s390/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/sh/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/sparc/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/tile/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1. * sysdeps/x86_64/nptl/tls.h: Define THREAD_GSCOPE_IN_TCB to 1.
* Update copyright dates with scripts/update-copyrights.Joseph Myers2018-01-015-5/+5
| | | | | | | * 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.
* nptl: Define __PTHREAD_MUTEX_{NUSERS_AFTER_KIND,USE_UNION}Adhemerval Zanella2017-11-071-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* nptl: Add tests for internal pthread_mutex_t offsetsAdhemerval Zanella2017-11-071-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a new build test to check for internal fields offsets for user visible internal field. Although currently the only field which is statically initialized to a non zero value is pthread_mutex_t.__data.__kind value, the tests also check the offset of __kind, __spins, __elision (if supported), and __list internal member. A internal header (pthread-offset.h) is added to each major ABI with the reference value. Checked on x86_64-linux-gnu and with a build check for all affected ABIs (aarch64-linux-gnu, alpha-linux-gnu, arm-linux-gnueabihf, hppa-linux-gnu, i686-linux-gnu, ia64-linux-gnu, m68k-linux-gnu, microblaze-linux-gnu, mips64-linux-gnu, mips64-n32-linux-gnu, mips-linux-gnu, powerpc64le-linux-gnu, powerpc-linux-gnu, s390-linux-gnu, s390x-linux-gnu, sh4-linux-gnu, sparc64-linux-gnu, sparcv9-linux-gnu, tilegx-linux-gnu, tilegx-linux-gnu-x32, tilepro-linux-gnu, x86_64-linux-gnu, and x86_64-linux-x32). * nptl/pthreadP.h (ASSERT_PTHREAD_STRING, ASSERT_PTHREAD_INTERNAL_OFFSET): New macro. * nptl/pthread_mutex_init.c (__pthread_mutex_init): Add build time checks for internal pthread_mutex_t offsets. * sysdeps/aarch64/nptl/pthread-offsets.h (__PTHREAD_MUTEX_NUSERS_OFFSET, __PTHREAD_MUTEX_KIND_OFFSET, __PTHREAD_MUTEX_SPINS_OFFSET, __PTHREAD_MUTEX_ELISION_OFFSET, __PTHREAD_MUTEX_LIST_OFFSET): New macro. * sysdeps/alpha/nptl/pthread-offsets.h: Likewise. * sysdeps/arm/nptl/pthread-offsets.h: Likewise. * sysdeps/hppa/nptl/pthread-offsets.h: Likewise. * sysdeps/i386/nptl/pthread-offsets.h: Likewise. * sysdeps/ia64/nptl/pthread-offsets.h: Likewise. * sysdeps/m68k/nptl/pthread-offsets.h: Likewise. * sysdeps/microblaze/nptl/pthread-offsets.h: Likewise. * sysdeps/mips/nptl/pthread-offsets.h: Likewise. * sysdeps/nios2/nptl/pthread-offsets.h: Likewise. * sysdeps/powerpc/nptl/pthread-offsets.h: Likewise. * sysdeps/s390/nptl/pthread-offsets.h: Likewise. * sysdeps/sh/nptl/pthread-offsets.h: Likewise. * sysdeps/sparc/nptl/pthread-offsets.h: Likewise. * sysdeps/tile/nptl/pthread-offsets.h: Likewise. * sysdeps/x86_64/nptl/pthread-offsets.h: Likewise. Signed-off-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Optimize generic spinlock code and use C11 like atomic macros.Stefan Liebler2017-06-061-24/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch optimizes the generic spinlock code. The type pthread_spinlock_t is a typedef to volatile int on all archs. Passing a volatile pointer to the atomic macros which are not mapped to the C11 atomic builtins can lead to extra stores and loads to stack if such a macro creates a temporary variable by using "__typeof (*(mem)) tmp;". Thus, those macros which are used by spinlock code - atomic_exchange_acquire, atomic_load_relaxed, atomic_compare_exchange_weak - have to be adjusted. According to the comment from Szabolcs Nagy, the type of a cast expression is unqualified (see http://www.open-std.org/jtc1/sc22/wg14/www/docs/dr_423.htm): __typeof ((__typeof (*(mem)) *(mem)) tmp; Thus from spinlock perspective the variable tmp is of type int instead of type volatile int. This patch adjusts those macros in include/atomic.h. With this construct GCC >= 5 omits the extra stores and loads. The atomic macros are replaced by the C11 like atomic macros and thus the code is aligned to it. The pthread_spin_unlock implementation is now using release memory order instead of sequentially consistent memory order. The issue with passed volatile int pointers applies to the C11 like atomic macros as well as the ones used before. I've added a glibc_likely hint to the first atomic exchange in pthread_spin_lock in order to return immediately to the caller if the lock is free. Without the hint, there is an additional jump if the lock is free. I've added the atomic_spin_nop macro within the loop of plain reads. The plain reads are also realized by C11 like atomic_load_relaxed macro. The new define ATOMIC_EXCHANGE_USES_CAS determines if the first try to acquire the spinlock in pthread_spin_lock or pthread_spin_trylock is an exchange or a CAS. This is defined in atomic-machine.h for all architectures. The define SPIN_LOCK_READS_BETWEEN_CMPXCHG is now removed. There is no technical reason for throwing in a CAS every now and then, and so far we have no evidence that it can improve performance. If that would be the case, we have to adjust other spin-waiting loops elsewhere, too! Using a CAS loop without plain reads is not a good idea on many targets and wasn't used by one. Thus there is now no option to do so. Architectures are now using the generic spinlock automatically if they do not provide an own implementation. Thus the pthread_spin_lock.c files in sysdeps folder are deleted. ChangeLog: * NEWS: Mention new spinlock implementation. * include/atomic.h: (__atomic_val_bysize): Cast type to omit volatile qualifier. (atomic_exchange_acq): Likewise. (atomic_load_relaxed): Likewise. (ATOMIC_EXCHANGE_USES_CAS): Check definition. * nptl/pthread_spin_init.c (pthread_spin_init): Use atomic_store_relaxed. * nptl/pthread_spin_lock.c (pthread_spin_lock): Use C11-like atomic macros. * nptl/pthread_spin_trylock.c (pthread_spin_trylock): Likewise. * nptl/pthread_spin_unlock.c (pthread_spin_unlock): Use atomic_store_release. * sysdeps/aarch64/nptl/pthread_spin_lock.c: Delete File. * sysdeps/arm/nptl/pthread_spin_lock.c: Likewise. * sysdeps/hppa/nptl/pthread_spin_lock.c: Likewise. * sysdeps/m68k/nptl/pthread_spin_lock.c: Likewise. * sysdeps/microblaze/nptl/pthread_spin_lock.c: Likewise. * sysdeps/mips/nptl/pthread_spin_lock.c: Likewise. * sysdeps/nios2/nptl/pthread_spin_lock.c: Likewise. * sysdeps/aarch64/atomic-machine.h (ATOMIC_EXCHANGE_USES_CAS): Define. * sysdeps/alpha/atomic-machine.h: Likewise. * sysdeps/arm/atomic-machine.h: Likewise. * sysdeps/i386/atomic-machine.h: Likewise. * sysdeps/ia64/atomic-machine.h: Likewise. * sysdeps/m68k/coldfire/atomic-machine.h: Likewise. * sysdeps/m68k/m680x0/m68020/atomic-machine.h: Likewise. * sysdeps/microblaze/atomic-machine.h: Likewise. * sysdeps/mips/atomic-machine.h: Likewise. * sysdeps/powerpc/powerpc32/atomic-machine.h: Likewise. * sysdeps/powerpc/powerpc64/atomic-machine.h: Likewise. * sysdeps/s390/atomic-machine.h: Likewise. * sysdeps/sparc/sparc32/atomic-machine.h: Likewise. * sysdeps/sparc/sparc32/sparcv9/atomic-machine.h: Likewise. * sysdeps/sparc/sparc64/atomic-machine.h: Likewise. * sysdeps/tile/tilegx/atomic-machine.h: Likewise. * sysdeps/tile/tilepro/atomic-machine.h: Likewise. * sysdeps/unix/sysv/linux/hppa/atomic-machine.h: Likewise. * sysdeps/unix/sysv/linux/m68k/coldfire/atomic-machine.h: Likewise. * sysdeps/unix/sysv/linux/nios2/atomic-machine.h: Likewise. * sysdeps/unix/sysv/linux/sh/atomic-machine.h: Likewise. * sysdeps/x86_64/atomic-machine.h: Likewise.
* Move shared pthread definitions to common headersAdhemerval Zanella2017-05-092-194/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* New pthread rwlock that is more scalable.Torvald Riegel2017-01-101-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This replaces the pthread rwlock with a new implementation that uses a more scalable algorithm (primarily through not using a critical section anymore to make state changes). The fast path for rdlock acquisition and release is now basically a single atomic read-modify write or CAS and a few branches. See nptl/pthread_rwlock_common.c for details. * nptl/DESIGN-rwlock.txt: Remove. * nptl/lowlevelrwlock.sym: Remove. * nptl/Makefile: Add new tests. * nptl/pthread_rwlock_common.c: New file. Contains the new rwlock. * nptl/pthreadP.h (PTHREAD_RWLOCK_PREFER_READER_P): Remove. (PTHREAD_RWLOCK_WRPHASE, PTHREAD_RWLOCK_WRLOCKED, PTHREAD_RWLOCK_RWAITING, PTHREAD_RWLOCK_READER_SHIFT, PTHREAD_RWLOCK_READER_OVERFLOW, PTHREAD_RWLOCK_WRHANDOVER, PTHREAD_RWLOCK_FUTEX_USED): New. * nptl/pthread_rwlock_init.c (__pthread_rwlock_init): Adapt to new implementation. * nptl/pthread_rwlock_rdlock.c (__pthread_rwlock_rdlock_slow): Remove. (__pthread_rwlock_rdlock): Adapt. * nptl/pthread_rwlock_timedrdlock.c (pthread_rwlock_timedrdlock): Adapt. * nptl/pthread_rwlock_timedwrlock.c (pthread_rwlock_timedwrlock): Adapt. * nptl/pthread_rwlock_trywrlock.c (pthread_rwlock_trywrlock): Adapt. * nptl/pthread_rwlock_tryrdlock.c (pthread_rwlock_tryrdlock): Adapt. * nptl/pthread_rwlock_unlock.c (pthread_rwlock_unlock): Adapt. * nptl/pthread_rwlock_wrlock.c (__pthread_rwlock_wrlock_slow): Remove. (__pthread_rwlock_wrlock): Adapt. * nptl/tst-rwlock10.c: Adapt. * nptl/tst-rwlock11.c: Adapt. * nptl/tst-rwlock17.c: New file. * nptl/tst-rwlock18.c: New file. * nptl/tst-rwlock19.c: New file. * nptl/tst-rwlock2b.c: New file. * nptl/tst-rwlock8.c: Adapt. * nptl/tst-rwlock9.c: Adapt. * sysdeps/aarch64/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/arm/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/hppa/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/ia64/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/m68k/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/microblaze/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/mips/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/nios2/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/s390/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/sh/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/sparc/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/tile/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/unix/sysv/linux/alpha/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * sysdeps/x86/bits/pthreadtypes.h (pthread_rwlock_t): Adapt. * nptl/nptl-printers.py (): Adapt. * nptl/nptl_lock_constants.pysym: Adapt. * nptl/test-rwlock-printers.py: Adapt. * nptl/test-rwlockattr-printers.c: Adapt. * nptl/test-rwlockattr-printers.py: Adapt.
* Update copyright dates with scripts/update-copyrights.Joseph Myers2017-01-016-6/+6
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* New condvar implementation that provides stronger ordering guarantees.Torvald Riegel2016-12-311-9/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* Remove cached PID/TID in cloneAdhemerval Zanella2016-11-241-1/+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.
* nptl: Document the reason why __kind in pthread_mutex_t is part of the ABIFlorian Weimer2016-11-071-1/+1
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* elf: Consolidate machine-agnostic DTV definitions in <dl-dtv.h>Florian Weimer2016-06-201-11/+1
| | | | | Identical definitions of dtv_t and TLS_DTV_UNALLOCATED were repeated for all architectures using DTVs.
* Update copyright dates with scripts/update-copyrights.Joseph Myers2016-01-046-6/+6
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* Update copyright dates with scripts/update-copyrights.Joseph Myers2015-01-026-6/+6
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* m68k: Consolidate nptl/ subdirectories under linux/...Roland McGrath2014-06-232-0/+215
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* m68k: Define TLS_DEFINE_INIT_TPRoland McGrath2014-06-091-0/+3
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* Remove second argument from TLS_INIT_TP macroAndreas Schwab2014-05-271-1/+1
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* Clean up __exit_thread.Roland McGrath2014-05-131-5/+0
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* Compile with -Wundef.Roland McGrath2014-03-141-0/+1
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* Move m68k from ports to libcAndreas Schwab2014-02-105-0/+261
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