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* nptl: Avoid fork handler lock for async-signal-safe fork [BZ #24161]Florian Weimer2019-02-081-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 27761a1042daf01987e7d79636d0c41511c6df3c ("Refactor atfork handlers") introduced a lock, atfork_lock, around fork handler list accesses. It turns out that this lock occasionally results in self-deadlocks in malloc/tst-mallocfork2: (gdb) bt #0 __lll_lock_wait_private () at ../sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:63 #1 0x00007f160c6f927a in __run_fork_handlers (who=(unknown: 209394016), who@entry=atfork_run_prepare) at register-atfork.c:116 #2 0x00007f160c6b7897 in __libc_fork () at ../sysdeps/nptl/fork.c:58 #3 0x00000000004027d6 in sigusr1_handler (signo=<optimized out>) at tst-mallocfork2.c:80 #4 sigusr1_handler (signo=<optimized out>) at tst-mallocfork2.c:64 #5 <signal handler called> #6 0x00007f160c6f92e4 in __run_fork_handlers (who=who@entry=atfork_run_parent) at register-atfork.c:136 #7 0x00007f160c6b79a2 in __libc_fork () at ../sysdeps/nptl/fork.c:152 #8 0x0000000000402567 in do_test () at tst-mallocfork2.c:156 #9 0x0000000000402dd2 in support_test_main (argc=1, argv=0x7ffc81ef1ab0, config=config@entry=0x7ffc81ef1970) at support_test_main.c:350 #10 0x0000000000402362 in main (argc=<optimized out>, argv=<optimized out>) at ../support/test-driver.c:168 If no locking happens in the single-threaded case (where fork is expected to be async-signal-safe), this deadlock is avoided. (pthread_atfork is not required to be async-signal-safe, so a fork call from a signal handler interrupting pthread_atfork is not a problem.)
* Update copyright dates with scripts/update-copyrights.Joseph Myers2019-01-011-1/+1
| | | | | | | * 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.
* Refactor atfork handlersAdhemerval Zanella2018-02-221-85/+89
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current implementation (sysdeps/nptl/fork.c) replicates the atfork handlers list backward to invoke the child handlers after fork/clone syscall. The internal atfork handlers is implemented as a single-linked list so a lock-free algorithm can be used, trading fork mulithread call performance for some code complexity and dynamic stack allocation (since the backwards list should not fail). This patch refactor it to use a dynarary instead of a linked list. It simplifies the external variables need to be exported and also the internal atfork handler member definition. The downside is a serialization of fork call in multithread, since to operate on the dynarray the internal lock should be used. However as noted by Florian, it already acquires external locks for malloc and libio so it is already hitting some lock contention. Besides, posix_spawn should be faster and more scalable to run external programs in multithread environments. Checked on x86_64-linux-gnu. * nptl/Makefile (routines): Remove unregister-atfork. * nptl/register-atfork.c (fork_handler_pool): Remove variable. (fork_handler_alloc): Remove function. (fork_handlers, fork_handler_init): New variables. (__fork_lock): Rename to atfork_lock. (__register_atfork, __unregister_atfork, libc_freeres_fn): Rewrite to use a dynamic array to add/remove atfork handlers. * sysdeps/nptl/fork.c (__libc_fork): Likewise. * sysdeps/nptl/fork.h (__fork_lock, __fork_handlers, __linkin_atfork): Remove declaration. (fork_handler): Remove next, refcntr, and need_signal member. (__run_fork_handler_type): New enum. (__run_fork_handlers): New prototype. * sysdeps/nptl/libc-lockP.h (__libc_atfork): Remove declaration.
* Update copyright dates with scripts/update-copyrights.Joseph Myers2018-01-011-1/+1
| | | | | | | * 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.
* Update copyright dates with scripts/update-copyrights.Joseph Myers2017-01-011-1/+1
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* Update copyright dates with scripts/update-copyrights.Joseph Myers2016-01-041-1/+1
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* Convert miscellaneous function definitions to prototype style.Joseph Myers2015-10-201-5/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch converts various miscellaneous functions definitions in glibc, found with grep and not covered by my previous scripted conversions, from old-style K&R to prototype-style. These changes were made manually. This is not necessarily exhaustive as formatting variants may have prevented my grep from finding some such definitions. Regarding the changes to files from GMP, they may originally have been omitted when removing __STDC__ conditionals because of the files coming from another package, but (a) GMP no longer has __STDC__ conditionals there anyway and (b) we don't try to keep these files verbatim in sync with GMP (and there are licensing differences), so making the change to them in glibc seems reasonable. Tested for x86_64 and x86 (testsuite - this patch affects files containing assertions). * debug/fortify_fail.c (__fortify_fail): Convert to prototype-style function definition. Use internal_function. * libio/genops.c (save_for_backup): Convert to prototype-style function definition. * libio/wgenops.c (save_for_wbackup): Likewise. * login/grantpt.c (grantpt): Likewise. * login/ptsname.c (ptsname): Likewise. (__ptsname_r): Likewise. * login/unlockpt.c (unlockpt): Likewise. * mach/msgserver.c (__mach_msg_server): Likewise. * misc/efgcvt.c (__APPEND (FUNC_PREFIX, fcvt)): Likewise. (__APPEND (FUNC_PREFIX, ecvt)): Likewise. (__APPEND (FUNC_PREFIX, gcvt)): Likewise. * misc/efgcvt_r.c (__APPEND (FUNC_PREFIX, fcvt_r)): Likewise. (__APPEND (FUNC_PREFIX, ecvt_r)): Likewise. * nptl/cleanup_compat.c (_pthread_cleanup_push): Likewise. * nptl/cleanup_defer_compat.c (_pthread_cleanup_push_defer): Likewise. * nptl/libc_pthread_init.c (__libc_pthread_init): Likewise. Use internal_function. * nptl/pthread_atfork.c (__pthread_atfork): Convert to prototype-style function definition. * nptl/pthread_create.c (__pthread_create_2_1): Likewise. [SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_1)] (__pthread_create_2_0): Likewise. * nptl/pthread_key_create.c (__pthread_key_create): Likewise. * nptl/register-atfork.c (__register_atfork): Likewise. * posix/glob.c (glob): Likewise. * posix/regcomp.c (re_comp): Likewise. * posix/regexec.c (re_exec): Likewise. * stdlib/add_n.c [__STDC__]: Make code unconditional. [!__STDC__]: Remove conditional code. * stdlib/cmp.c [__STDC__]: Make code unconditional. [!__STDC__]: Remove conditional code. * stdlib/divmod_1.c [__STDC__]: Make code unconditional. [!__STDC__]: Remove conditional code. * stdlib/divrem.c [__STDC__]: Make code unconditional. [!__STDC__]: Remove conditional code. * stdlib/lshift.c [__STDC__]: Make code unconditional. [!__STDC__]: Remove conditional code. * stdlib/mod_1.c [__STDC__]: Make code unconditional. [!__STDC__]: Remove conditional code. * stdlib/mul.c [__STDC__]: Make code unconditional. [!__STDC__]: Remove conditional code. * stdlib/mul_n.c [__STDC__]: Make code unconditional. [!__STDC__]: Remove conditional code. * stdlib/rshift.c [__STDC__]: Make code unconditional. [!__STDC__]: Remove conditional code. * stdlib/strtod.c (INTERNAL (STRTOF)): Convert to prototype-style function definition. (STRTOF): Likewise. * stdlib/strtod_l.c (__STRTOF): Likewise. * stdlib/strtol.c (INTERNAL (strtol)): Likewise. * stdlib/strtol_l.c (INTERNAL (__strtol_l)): Likewise. (__strtol_l): Likewise. * stdlib/sub_n.c [__STDC__]: Make code unconditional. [!__STDC__]: Remove conditional code. * string/memrchr.c (MEMRCHR): Convert to prototype-style function definition. * string/strcasecmp.c (LOCALE_PARAM_DECL): Remove macro. [USE_IN_EXTENDED_LOCALE_MODEL] (LOCALE_PARAM): Include argument type. (__strcasecmp): Convert to prototype-style function definition. * string/strncase.c (LOCALE_PARAM_DECL): Remove macro. [USE_IN_EXTENDED_LOCALE_MODEL] (LOCALE_PARAM): Include argument type. (__strncasecmp): Convert to prototype-style function definition. * sunrpc/pm_getport.c (__libc_rpc_getport): Likewise. * sunrpc/xdr.c (xdr_union): Likewise. * sunrpc/xdr_array.c (xdr_array): Likewise. * sunrpc/xdr_ref.c (xdr_reference): Likewise. * sysdeps/m68k/m680x0/fpu/s_atan.c (__CONCATX(__,FUNC)): Likewise. * sysdeps/m68k/m680x0/fpu/s_isinf.c (__CONCATX(__,FUNC)): Likewise. * sysdeps/m68k/m680x0/fpu/s_scalbn.c (__CONCATX(__scalbn,suffix): Likewise. * sysdeps/m68k/m680x0/fpu/s_sincos.c (CONCATX(__,FUNC)): Likewise. * sysdeps/unix/sysv/linux/i386/scandir64.c (__old_scandir64): Likewise. * time/strftime_l.c (LOCALE_PARAM_DECL): Remove macro. (LOCALE_PARAM_PROTO): Likewise. [_LIBC && USE_IN_EXTENDED_LOCALE_MODEL] (LOCALE_PARAM): Include argument type. (ut_argument_spec): Remove macro. (ut_argument_spec_iso): Rename to ut_argument_spec. (memcpy_lowcase): Use LOCALE_PARAM in declaration. Convert to prototype-style function definition. (memcpy_uppcase): Likewise. (__strftime_internal): Likewise. (my_strftime): Likewise. * time/strptime_l.c (LOCALE_PARAM_PROTO): Remove macro. (LOCALE_PARAM_DECL): Likewise. [_LIBC] (LOCALE_PARAM): Include argument type. (__strptime_internal): Convert to prototype-style function definition. (strptime): Likewise. * wcsmbs/wcscasecmp.c (LOCALE_PARAM_DECL): Remove macro. [USE_IN_EXTENDED_LOCALE_MODEL] (LOCALE_PARAM): Include argument type. (__wcscasecmp): Convert to prototype-style function definition. * wcsmbs/wcsncase.c (LOCALE_PARAM_DECL): Remove macro. [USE_IN_EXTENDED_LOCALE_MODEL] (LOCALE_PARAM): Include argument type. (__wcsncasecmp): Convert to prototype-style function definition.
* Update copyright dates with scripts/update-copyrights.Joseph Myers2015-01-021-1/+1
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* NPTL: Move fork state variables to initializer files.Roland McGrath2014-12-171-0/+2
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* Get rid of nptl/sysdeps/ entirely!Roland McGrath2014-07-071-0/+145