479 lines
17 KiB
C
479 lines
17 KiB
C
/* Copyright (C) 2002-2014 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <assert.h>
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#include <errno.h>
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#include <limits.h>
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#include <signal.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <sys/param.h>
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#include <sys/resource.h>
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#include <pthreadP.h>
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#include <atomic.h>
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#include <ldsodefs.h>
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#include <tls.h>
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#include <list.h>
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#include <fork.h>
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#include <version.h>
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#include <shlib-compat.h>
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#include <smp.h>
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#include <lowlevellock.h>
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#include <kernel-features.h>
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/* Size and alignment of static TLS block. */
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size_t __static_tls_size;
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size_t __static_tls_align_m1;
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#ifndef __ASSUME_SET_ROBUST_LIST
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/* Negative if we do not have the system call and we can use it. */
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int __set_robust_list_avail;
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# define set_robust_list_not_avail() \
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__set_robust_list_avail = -1
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#else
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# define set_robust_list_not_avail() do { } while (0)
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#endif
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#ifndef __ASSUME_FUTEX_CLOCK_REALTIME
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/* Nonzero if we do not have FUTEX_CLOCK_REALTIME. */
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int __have_futex_clock_realtime;
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# define __set_futex_clock_realtime() \
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__have_futex_clock_realtime = 1
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#else
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#define __set_futex_clock_realtime() do { } while (0)
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#endif
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/* Version of the library, used in libthread_db to detect mismatches. */
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static const char nptl_version[] __attribute_used__ = VERSION;
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#ifndef SHARED
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extern void __libc_setup_tls (size_t tcbsize, size_t tcbalign);
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#endif
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#ifdef SHARED
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static
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#else
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extern
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#endif
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void __nptl_set_robust (struct pthread *);
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#ifdef SHARED
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static void nptl_freeres (void);
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static const struct pthread_functions pthread_functions =
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{
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.ptr_pthread_attr_destroy = __pthread_attr_destroy,
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# if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_1)
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.ptr___pthread_attr_init_2_0 = __pthread_attr_init_2_0,
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# endif
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.ptr___pthread_attr_init_2_1 = __pthread_attr_init_2_1,
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.ptr_pthread_attr_getdetachstate = __pthread_attr_getdetachstate,
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.ptr_pthread_attr_setdetachstate = __pthread_attr_setdetachstate,
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.ptr_pthread_attr_getinheritsched = __pthread_attr_getinheritsched,
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.ptr_pthread_attr_setinheritsched = __pthread_attr_setinheritsched,
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.ptr_pthread_attr_getschedparam = __pthread_attr_getschedparam,
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.ptr_pthread_attr_setschedparam = __pthread_attr_setschedparam,
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.ptr_pthread_attr_getschedpolicy = __pthread_attr_getschedpolicy,
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.ptr_pthread_attr_setschedpolicy = __pthread_attr_setschedpolicy,
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.ptr_pthread_attr_getscope = __pthread_attr_getscope,
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.ptr_pthread_attr_setscope = __pthread_attr_setscope,
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.ptr_pthread_condattr_destroy = __pthread_condattr_destroy,
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.ptr_pthread_condattr_init = __pthread_condattr_init,
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.ptr___pthread_cond_broadcast = __pthread_cond_broadcast,
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.ptr___pthread_cond_destroy = __pthread_cond_destroy,
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.ptr___pthread_cond_init = __pthread_cond_init,
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.ptr___pthread_cond_signal = __pthread_cond_signal,
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.ptr___pthread_cond_wait = __pthread_cond_wait,
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.ptr___pthread_cond_timedwait = __pthread_cond_timedwait,
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# if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_3_2)
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.ptr___pthread_cond_broadcast_2_0 = __pthread_cond_broadcast_2_0,
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.ptr___pthread_cond_destroy_2_0 = __pthread_cond_destroy_2_0,
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.ptr___pthread_cond_init_2_0 = __pthread_cond_init_2_0,
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.ptr___pthread_cond_signal_2_0 = __pthread_cond_signal_2_0,
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.ptr___pthread_cond_wait_2_0 = __pthread_cond_wait_2_0,
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.ptr___pthread_cond_timedwait_2_0 = __pthread_cond_timedwait_2_0,
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# endif
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.ptr_pthread_equal = __pthread_equal,
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.ptr___pthread_exit = __pthread_exit,
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.ptr_pthread_getschedparam = __pthread_getschedparam,
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.ptr_pthread_setschedparam = __pthread_setschedparam,
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.ptr_pthread_mutex_destroy = __pthread_mutex_destroy,
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.ptr_pthread_mutex_init = __pthread_mutex_init,
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.ptr_pthread_mutex_lock = __pthread_mutex_lock,
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.ptr_pthread_mutex_unlock = __pthread_mutex_unlock,
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.ptr_pthread_self = __pthread_self,
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.ptr_pthread_setcancelstate = __pthread_setcancelstate,
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.ptr_pthread_setcanceltype = __pthread_setcanceltype,
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.ptr___pthread_cleanup_upto = __pthread_cleanup_upto,
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.ptr___pthread_once = __pthread_once,
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.ptr___pthread_rwlock_rdlock = __pthread_rwlock_rdlock,
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.ptr___pthread_rwlock_wrlock = __pthread_rwlock_wrlock,
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.ptr___pthread_rwlock_unlock = __pthread_rwlock_unlock,
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.ptr___pthread_key_create = __pthread_key_create,
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.ptr___pthread_getspecific = __pthread_getspecific,
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.ptr___pthread_setspecific = __pthread_setspecific,
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.ptr__pthread_cleanup_push_defer = __pthread_cleanup_push_defer,
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.ptr__pthread_cleanup_pop_restore = __pthread_cleanup_pop_restore,
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.ptr_nthreads = &__nptl_nthreads,
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.ptr___pthread_unwind = &__pthread_unwind,
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.ptr__nptl_deallocate_tsd = __nptl_deallocate_tsd,
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.ptr__nptl_setxid = __nptl_setxid,
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/* For now only the stack cache needs to be freed. */
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.ptr_freeres = nptl_freeres,
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.ptr_set_robust = __nptl_set_robust
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};
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# define ptr_pthread_functions &pthread_functions
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#else
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# define ptr_pthread_functions NULL
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#endif
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#ifdef SHARED
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/* This function is called indirectly from the freeres code in libc. */
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static void
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__libc_freeres_fn_section
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nptl_freeres (void)
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{
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__unwind_freeres ();
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__free_stacks (0);
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}
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static
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#endif
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void
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__nptl_set_robust (struct pthread *self)
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{
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INTERNAL_SYSCALL_DECL (err);
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INTERNAL_SYSCALL (set_robust_list, err, 2, &self->robust_head,
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sizeof (struct robust_list_head));
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}
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/* For asynchronous cancellation we use a signal. This is the handler. */
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static void
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sigcancel_handler (int sig, siginfo_t *si, void *ctx)
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{
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/* Determine the process ID. It might be negative if the thread is
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in the middle of a fork() call. */
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pid_t pid = THREAD_GETMEM (THREAD_SELF, pid);
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if (__glibc_unlikely (pid < 0))
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pid = -pid;
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/* Safety check. It would be possible to call this function for
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other signals and send a signal from another process. This is not
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correct and might even be a security problem. Try to catch as
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many incorrect invocations as possible. */
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if (sig != SIGCANCEL
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|| si->si_pid != pid
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|| si->si_code != SI_TKILL)
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return;
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struct pthread *self = THREAD_SELF;
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int oldval = THREAD_GETMEM (self, cancelhandling);
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while (1)
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{
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/* We are canceled now. When canceled by another thread this flag
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is already set but if the signal is directly send (internally or
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from another process) is has to be done here. */
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int newval = oldval | CANCELING_BITMASK | CANCELED_BITMASK;
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if (oldval == newval || (oldval & EXITING_BITMASK) != 0)
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/* Already canceled or exiting. */
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break;
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int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval,
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oldval);
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if (curval == oldval)
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{
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/* Set the return value. */
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THREAD_SETMEM (self, result, PTHREAD_CANCELED);
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/* Make sure asynchronous cancellation is still enabled. */
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if ((newval & CANCELTYPE_BITMASK) != 0)
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/* Run the registered destructors and terminate the thread. */
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__do_cancel ();
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break;
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}
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oldval = curval;
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}
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}
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struct xid_command *__xidcmd attribute_hidden;
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/* We use the SIGSETXID signal in the setuid, setgid, etc. implementations to
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tell each thread to call the respective setxid syscall on itself. This is
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the handler. */
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static void
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sighandler_setxid (int sig, siginfo_t *si, void *ctx)
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{
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/* Determine the process ID. It might be negative if the thread is
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in the middle of a fork() call. */
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pid_t pid = THREAD_GETMEM (THREAD_SELF, pid);
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int result;
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if (__glibc_unlikely (pid < 0))
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pid = -pid;
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/* Safety check. It would be possible to call this function for
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other signals and send a signal from another process. This is not
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correct and might even be a security problem. Try to catch as
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many incorrect invocations as possible. */
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if (sig != SIGSETXID
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|| si->si_pid != pid
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|| si->si_code != SI_TKILL)
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return;
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INTERNAL_SYSCALL_DECL (err);
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result = INTERNAL_SYSCALL_NCS (__xidcmd->syscall_no, err, 3, __xidcmd->id[0],
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__xidcmd->id[1], __xidcmd->id[2]);
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int error = 0;
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if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result, err)))
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error = INTERNAL_SYSCALL_ERRNO (result, err);
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__nptl_setxid_error (__xidcmd, error);
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/* Reset the SETXID flag. */
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struct pthread *self = THREAD_SELF;
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int flags, newval;
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do
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{
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flags = THREAD_GETMEM (self, cancelhandling);
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newval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling,
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flags & ~SETXID_BITMASK, flags);
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}
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while (flags != newval);
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/* And release the futex. */
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self->setxid_futex = 1;
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lll_futex_wake (&self->setxid_futex, 1, LLL_PRIVATE);
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if (atomic_decrement_val (&__xidcmd->cntr) == 0)
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lll_futex_wake (&__xidcmd->cntr, 1, LLL_PRIVATE);
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}
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/* When using __thread for this, we do it in libc so as not
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to give libpthread its own TLS segment just for this. */
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extern void **__libc_dl_error_tsd (void) __attribute__ ((const));
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/* This can be set by the debugger before initialization is complete. */
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static bool __nptl_initial_report_events __attribute_used__;
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void
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__pthread_initialize_minimal_internal (void)
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{
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#ifndef SHARED
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/* Unlike in the dynamically linked case the dynamic linker has not
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taken care of initializing the TLS data structures. */
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__libc_setup_tls (TLS_TCB_SIZE, TLS_TCB_ALIGN);
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/* We must prevent gcc from being clever and move any of the
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following code ahead of the __libc_setup_tls call. This function
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will initialize the thread register which is subsequently
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used. */
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__asm __volatile ("");
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#endif
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/* Minimal initialization of the thread descriptor. */
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struct pthread *pd = THREAD_SELF;
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INTERNAL_SYSCALL_DECL (err);
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pd->pid = pd->tid = INTERNAL_SYSCALL (set_tid_address, err, 1, &pd->tid);
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THREAD_SETMEM (pd, specific[0], &pd->specific_1stblock[0]);
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THREAD_SETMEM (pd, user_stack, true);
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if (LLL_LOCK_INITIALIZER != 0)
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THREAD_SETMEM (pd, lock, LLL_LOCK_INITIALIZER);
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#if HP_TIMING_AVAIL
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THREAD_SETMEM (pd, cpuclock_offset, GL(dl_cpuclock_offset));
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#endif
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/* Initialize the robust mutex data. */
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#ifdef __PTHREAD_MUTEX_HAVE_PREV
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pd->robust_prev = &pd->robust_head;
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#endif
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pd->robust_head.list = &pd->robust_head;
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#ifdef __NR_set_robust_list
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pd->robust_head.futex_offset = (offsetof (pthread_mutex_t, __data.__lock)
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- offsetof (pthread_mutex_t,
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__data.__list.__next));
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int res = INTERNAL_SYSCALL (set_robust_list, err, 2, &pd->robust_head,
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sizeof (struct robust_list_head));
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if (INTERNAL_SYSCALL_ERROR_P (res, err))
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#endif
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set_robust_list_not_avail ();
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#ifndef __ASSUME_PRIVATE_FUTEX
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/* Private futexes are always used (at least internally) so that
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doing the test once this early is beneficial. */
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{
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int word = 0;
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word = INTERNAL_SYSCALL (futex, err, 3, &word,
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FUTEX_WAKE | FUTEX_PRIVATE_FLAG, 1);
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if (!INTERNAL_SYSCALL_ERROR_P (word, err))
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THREAD_SETMEM (pd, header.private_futex, FUTEX_PRIVATE_FLAG);
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}
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/* Private futexes have been introduced earlier than the
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FUTEX_CLOCK_REALTIME flag. We don't have to run the test if we
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know the former are not supported. This also means we know the
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kernel will return ENOSYS for unknown operations. */
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if (THREAD_GETMEM (pd, header.private_futex) != 0)
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#endif
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#ifndef __ASSUME_FUTEX_CLOCK_REALTIME
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{
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int word = 0;
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/* NB: the syscall actually takes six parameters. The last is the
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bit mask. But since we will not actually wait at all the value
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is irrelevant. Given that passing six parameters is difficult
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on some architectures we just pass whatever random value the
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calling convention calls for to the kernel. It causes no harm. */
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word = INTERNAL_SYSCALL (futex, err, 5, &word,
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FUTEX_WAIT_BITSET | FUTEX_CLOCK_REALTIME
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| FUTEX_PRIVATE_FLAG, 1, NULL, 0);
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assert (INTERNAL_SYSCALL_ERROR_P (word, err));
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if (INTERNAL_SYSCALL_ERRNO (word, err) != ENOSYS)
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__set_futex_clock_realtime ();
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}
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#endif
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/* Set initial thread's stack block from 0 up to __libc_stack_end.
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It will be bigger than it actually is, but for unwind.c/pt-longjmp.c
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purposes this is good enough. */
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THREAD_SETMEM (pd, stackblock_size, (size_t) __libc_stack_end);
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/* Initialize the list of all running threads with the main thread. */
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INIT_LIST_HEAD (&__stack_user);
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list_add (&pd->list, &__stack_user);
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/* Before initializing __stack_user, the debugger could not find us and
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had to set __nptl_initial_report_events. Propagate its setting. */
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THREAD_SETMEM (pd, report_events, __nptl_initial_report_events);
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/* Install the cancellation signal handler. If for some reason we
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cannot install the handler we do not abort. Maybe we should, but
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it is only asynchronous cancellation which is affected. */
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struct sigaction sa;
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sa.sa_sigaction = sigcancel_handler;
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sa.sa_flags = SA_SIGINFO;
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__sigemptyset (&sa.sa_mask);
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(void) __libc_sigaction (SIGCANCEL, &sa, NULL);
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/* Install the handle to change the threads' uid/gid. */
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sa.sa_sigaction = sighandler_setxid;
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sa.sa_flags = SA_SIGINFO | SA_RESTART;
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(void) __libc_sigaction (SIGSETXID, &sa, NULL);
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/* The parent process might have left the signals blocked. Just in
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case, unblock it. We reuse the signal mask in the sigaction
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structure. It is already cleared. */
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__sigaddset (&sa.sa_mask, SIGCANCEL);
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__sigaddset (&sa.sa_mask, SIGSETXID);
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(void) INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_UNBLOCK, &sa.sa_mask,
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NULL, _NSIG / 8);
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/* Get the size of the static and alignment requirements for the TLS
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block. */
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size_t static_tls_align;
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_dl_get_tls_static_info (&__static_tls_size, &static_tls_align);
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/* Make sure the size takes all the alignments into account. */
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if (STACK_ALIGN > static_tls_align)
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static_tls_align = STACK_ALIGN;
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__static_tls_align_m1 = static_tls_align - 1;
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__static_tls_size = roundup (__static_tls_size, static_tls_align);
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/* Determine the default allowed stack size. This is the size used
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in case the user does not specify one. */
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struct rlimit limit;
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if (getrlimit (RLIMIT_STACK, &limit) != 0
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|| limit.rlim_cur == RLIM_INFINITY)
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/* The system limit is not usable. Use an architecture-specific
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default. */
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limit.rlim_cur = ARCH_STACK_DEFAULT_SIZE;
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else if (limit.rlim_cur < PTHREAD_STACK_MIN)
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/* The system limit is unusably small.
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Use the minimal size acceptable. */
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limit.rlim_cur = PTHREAD_STACK_MIN;
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/* Make sure it meets the minimum size that allocate_stack
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(allocatestack.c) will demand, which depends on the page size. */
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const uintptr_t pagesz = GLRO(dl_pagesize);
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const size_t minstack = pagesz + __static_tls_size + MINIMAL_REST_STACK;
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if (limit.rlim_cur < minstack)
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limit.rlim_cur = minstack;
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/* Round the resource limit up to page size. */
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limit.rlim_cur = (limit.rlim_cur + pagesz - 1) & -pagesz;
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lll_lock (__default_pthread_attr_lock, LLL_PRIVATE);
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__default_pthread_attr.stacksize = limit.rlim_cur;
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__default_pthread_attr.guardsize = GLRO (dl_pagesize);
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lll_unlock (__default_pthread_attr_lock, LLL_PRIVATE);
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#ifdef SHARED
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/* Transfer the old value from the dynamic linker's internal location. */
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*__libc_dl_error_tsd () = *(*GL(dl_error_catch_tsd)) ();
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GL(dl_error_catch_tsd) = &__libc_dl_error_tsd;
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/* Make __rtld_lock_{,un}lock_recursive use pthread_mutex_{,un}lock,
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keep the lock count from the ld.so implementation. */
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GL(dl_rtld_lock_recursive) = (void *) __pthread_mutex_lock;
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GL(dl_rtld_unlock_recursive) = (void *) __pthread_mutex_unlock;
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unsigned int rtld_lock_count = GL(dl_load_lock).mutex.__data.__count;
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GL(dl_load_lock).mutex.__data.__count = 0;
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while (rtld_lock_count-- > 0)
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__pthread_mutex_lock (&GL(dl_load_lock).mutex);
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GL(dl_make_stack_executable_hook) = &__make_stacks_executable;
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#endif
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GL(dl_init_static_tls) = &__pthread_init_static_tls;
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GL(dl_wait_lookup_done) = &__wait_lookup_done;
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/* Register the fork generation counter with the libc. */
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|
#ifndef TLS_MULTIPLE_THREADS_IN_TCB
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__libc_multiple_threads_ptr =
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#endif
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__libc_pthread_init (&__fork_generation, __reclaim_stacks,
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ptr_pthread_functions);
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|
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|
/* Determine whether the machine is SMP or not. */
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|
__is_smp = is_smp_system ();
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}
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|
strong_alias (__pthread_initialize_minimal_internal,
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|
__pthread_initialize_minimal)
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size_t
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__pthread_get_minstack (const pthread_attr_t *attr)
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|
{
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struct pthread_attr *iattr = (struct pthread_attr *) attr;
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|
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return (GLRO(dl_pagesize) + __static_tls_size + PTHREAD_STACK_MIN
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+ iattr->guardsize);
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}
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