Commit Graph

6 Commits

Author SHA1 Message Date
Florian Weimer
27a448223c nptl: Move core mutex functions into libc
This is complicated because of a second compilation of
nptl/pthread_mutex_lock.c via nptl/pthread_mutex_cond_lock.c.
PTHREAD_MUTEX_VERSIONS is introduced to suppress symbol versions
in that case.

The symbols __pthread_mutex_lock, __pthread_mutex_unlock,
__pthread_mutex_init, __pthread_mutex_destroy, pthread_mutex_lock,
pthread_mutex_unlock, pthread_mutex_init, pthread_mutex_destroy
have been moved using scripts/move-symbol-to-libc.py.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-04-21 19:49:51 +02:00
Florian Weimer
99f841c441 nptl: pthread_mutex_lock, pthread_mutex_unock single-threaded optimization
This is optimization is similar in spirit to the SINGLE_THREAD_P check
in the malloc implementation.  Doing this in generic code allows us
to prioritize those cases which are likely to occur in single-threaded
programs (normal and recursive mutexes).

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-04-21 19:49:51 +02:00
Florian Weimer
83b09837ed nptl: Remove internal_function attribute 2017-08-31 18:52:00 +02:00
Torvald Riegel
65810f0ef0 robust mutexes: Fix broken x86 assembly by removing it
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.
2017-01-13 17:16:07 +01:00
Joseph Myers
9dd346ff43 Convert 113 more function definitions to prototype style (files with assertions).
This mostly automatically-generated patch converts 113 function
definitions in glibc from old-style K&R to prototype-style.  Following
my other recent such patches, this one deals with the case of function
definitions in files that either contain assertions or where grep
suggested they might contain assertions - and thus where it isn't
possible to use a simple object code comparison as a sanity check on
the correctness of the patch, because line numbers are changed.

A few such automatically-generated changes needed to be supplemented
by manual changes for the result to compile.  openat64 had a prototype
declaration with "..." but an old-style definition in
sysdeps/unix/sysv/linux/dl-openat64.c, and "..." needed adding to the
generated prototype in the definition (I've filed
<https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68024> for diagnosing
such cases in GCC; the old state was undefined behavior not requiring
a diagnostic, but one seems a good idea).  In addition, as Florian has
noted regparm attribute mismatches between declaration and definition
are only diagnosed for prototype definitions, and five functions
needed internal_function added to their definitions (in the case of
__pthread_mutex_cond_lock, via the macro definition of
__pthread_mutex_lock) to compile on i386.

After this patch is in, remaining old-style definitions are probably
most readily fixed manually before we can turn on
-Wold-style-definition for all builds.

Tested for x86_64 and x86 (testsuite).

	* crypt/md5-crypt.c (__md5_crypt_r): Convert to prototype-style
	function definition.
	* crypt/sha256-crypt.c (__sha256_crypt_r): Likewise.
	* crypt/sha512-crypt.c (__sha512_crypt_r): Likewise.
	* debug/backtracesyms.c (__backtrace_symbols): Likewise.
	* elf/dl-minimal.c (_itoa): Likewise.
	* hurd/hurdmalloc.c (malloc): Likewise.
	(free): Likewise.
	(realloc): Likewise.
	* inet/inet6_option.c (inet6_option_space): Likewise.
	(inet6_option_init): Likewise.
	(inet6_option_append): Likewise.
	(inet6_option_alloc): Likewise.
	(inet6_option_next): Likewise.
	(inet6_option_find): Likewise.
	* io/ftw.c (FTW_NAME): Likewise.
	(NFTW_NAME): Likewise.
	(NFTW_NEW_NAME): Likewise.
	(NFTW_OLD_NAME): Likewise.
	* libio/iofwide.c (_IO_fwide): Likewise.
	* libio/strops.c (_IO_str_init_static_internal): Likewise.
	(_IO_str_init_static): Likewise.
	(_IO_str_init_readonly): Likewise.
	(_IO_str_overflow): Likewise.
	(_IO_str_underflow): Likewise.
	(_IO_str_count): Likewise.
	(_IO_str_seekoff): Likewise.
	(_IO_str_pbackfail): Likewise.
	(_IO_str_finish): Likewise.
	* libio/wstrops.c (_IO_wstr_init_static): Likewise.
	(_IO_wstr_overflow): Likewise.
	(_IO_wstr_underflow): Likewise.
	(_IO_wstr_count): Likewise.
	(_IO_wstr_seekoff): Likewise.
	(_IO_wstr_pbackfail): Likewise.
	(_IO_wstr_finish): Likewise.
	* locale/programs/localedef.c (normalize_codeset): Likewise.
	* locale/programs/locarchive.c (add_locale_to_archive): Likewise.
	(add_locales_to_archive): Likewise.
	(delete_locales_from_archive): Likewise.
	* malloc/malloc.c (__libc_mallinfo): Likewise.
	* math/gen-auto-libm-tests.c (init_fp_formats): Likewise.
	* misc/tsearch.c (__tfind): Likewise.
	* nptl/pthread_attr_destroy.c (__pthread_attr_destroy): Likewise.
	* nptl/pthread_attr_getdetachstate.c
	(__pthread_attr_getdetachstate): Likewise.
	* nptl/pthread_attr_getguardsize.c (pthread_attr_getguardsize):
	Likewise.
	* nptl/pthread_attr_getinheritsched.c
	(__pthread_attr_getinheritsched): Likewise.
	* nptl/pthread_attr_getschedparam.c
	(__pthread_attr_getschedparam): Likewise.
	* nptl/pthread_attr_getschedpolicy.c
	(__pthread_attr_getschedpolicy): Likewise.
	* nptl/pthread_attr_getscope.c (__pthread_attr_getscope):
	Likewise.
	* nptl/pthread_attr_getstack.c (__pthread_attr_getstack):
	Likewise.
	* nptl/pthread_attr_getstackaddr.c (__pthread_attr_getstackaddr):
	Likewise.
	* nptl/pthread_attr_getstacksize.c (__pthread_attr_getstacksize):
	Likewise.
	* nptl/pthread_attr_init.c (__pthread_attr_init_2_1): Likewise.
	(__pthread_attr_init_2_0): Likewise.
	* nptl/pthread_attr_setdetachstate.c
	(__pthread_attr_setdetachstate): Likewise.
	* nptl/pthread_attr_setguardsize.c (pthread_attr_setguardsize):
	Likewise.
	* nptl/pthread_attr_setinheritsched.c
	(__pthread_attr_setinheritsched): Likewise.
	* nptl/pthread_attr_setschedparam.c
	(__pthread_attr_setschedparam): Likewise.
	* nptl/pthread_attr_setschedpolicy.c
	(__pthread_attr_setschedpolicy): Likewise.
	* nptl/pthread_attr_setscope.c (__pthread_attr_setscope):
	Likewise.
	* nptl/pthread_attr_setstack.c (__pthread_attr_setstack):
	Likewise.
	* nptl/pthread_attr_setstackaddr.c (__pthread_attr_setstackaddr):
	Likewise.
	* nptl/pthread_attr_setstacksize.c (__pthread_attr_setstacksize):
	Likewise.
	* nptl/pthread_condattr_setclock.c (pthread_condattr_setclock):
	Likewise.
	* nptl/pthread_create.c (__find_in_stack_list): Likewise.
	* nptl/pthread_getattr_np.c (pthread_getattr_np): Likewise.
	* nptl/pthread_mutex_cond_lock.c (__pthread_mutex_lock): Define to
	use internal_function.
	* nptl/pthread_mutex_init.c (__pthread_mutex_init): Convert to
	prototype-style function definition.
	* nptl/pthread_mutex_lock.c (__pthread_mutex_lock): Likewise.
	(__pthread_mutex_cond_lock_adjust): Likewise.  Use
	internal_function.
	* nptl/pthread_mutex_timedlock.c (pthread_mutex_timedlock):
	Convert to prototype-style function definition.
	* nptl/pthread_mutex_trylock.c (__pthread_mutex_trylock):
	Likewise.
	* nptl/pthread_mutex_unlock.c (__pthread_mutex_unlock_usercnt):
	Likewise.
	(__pthread_mutex_unlock): Likewise.
	* nptl_db/td_ta_clear_event.c (td_ta_clear_event): Likewise.
	* nptl_db/td_ta_set_event.c (td_ta_set_event): Likewise.
	* nptl_db/td_thr_clear_event.c (td_thr_clear_event): Likewise.
	* nptl_db/td_thr_event_enable.c (td_thr_event_enable): Likewise.
	* nptl_db/td_thr_set_event.c (td_thr_set_event): Likewise.
	* nss/makedb.c (process_input): Likewise.
	* posix/fnmatch.c (__strchrnul): Likewise.
	(__wcschrnul): Likewise.
	(fnmatch): Likewise.
	* posix/fnmatch_loop.c (FCT): Likewise.
	* posix/glob.c (globfree): Likewise.
	(__glob_pattern_type): Likewise.
	(__glob_pattern_p): Likewise.
	* posix/regcomp.c (re_compile_pattern): Likewise.
	(re_set_syntax): Likewise.
	(re_compile_fastmap): Likewise.
	(regcomp): Likewise.
	(regerror): Likewise.
	(regfree): Likewise.
	* posix/regexec.c (regexec): Likewise.
	(re_match): Likewise.
	(re_search): Likewise.
	(re_match_2): Likewise.
	(re_search_2): Likewise.
	(re_search_stub): Likewise.  Use internal_function
	(re_copy_regs): Likewise.
	(re_set_registers): Convert to prototype-style function
	definition.
	(prune_impossible_nodes): Likewise.  Use internal_function.
	* resolv/inet_net_pton.c (inet_net_pton): Convert to
	prototype-style function definition.
	(inet_net_pton_ipv4): Likewise.
	* stdlib/strtod_l.c (____STRTOF_INTERNAL): Likewise.
	* sysdeps/pthread/aio_cancel.c (aio_cancel): Likewise.
	* sysdeps/pthread/aio_suspend.c (aio_suspend): Likewise.
	* sysdeps/pthread/timer_delete.c (timer_delete): Likewise.
	* sysdeps/unix/sysv/linux/dl-openat64.c (openat64): Likewise.
	Make variadic.
	* time/strptime_l.c (localtime_r): Convert to prototype-style
	function definition.
	* wcsmbs/mbsnrtowcs.c (__mbsnrtowcs): Likewise.
	* wcsmbs/mbsrtowcs_l.c (__mbsrtowcs_l): Likewise.
	* wcsmbs/wcsnrtombs.c (__wcsnrtombs): Likewise.
	* wcsmbs/wcsrtombs.c (__wcsrtombs): Likewise.
2015-10-20 11:54:09 +00:00
Roland McGrath
08192659bb Get rid of nptl/sysdeps/ entirely! 2014-07-07 09:28:38 -07:00