1 /* Copyright (C) 2002-2007, 2008, 2009 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
26 #include <sys/param.h>
27 #include <sys/resource.h>
35 #include <lowlevellock.h>
36 #include <bits/kernel-features.h>
38 extern __typeof(sigaction) __libc_sigaction;
40 /* Size and alignment of static TLS block. */
41 size_t __static_tls_size;
42 size_t __static_tls_align_m1;
44 #ifndef __ASSUME_SET_ROBUST_LIST
45 /* Negative if we do not have the system call and we can use it. */
46 int __set_robust_list_avail;
47 # define set_robust_list_not_avail() \
48 __set_robust_list_avail = -1
50 # define set_robust_list_not_avail() do { } while (0)
53 #ifndef __ASSUME_FUTEX_CLOCK_REALTIME
54 /* Nonzero if we do not have FUTEX_CLOCK_REALTIME. */
55 int __have_futex_clock_realtime;
56 # define __set_futex_clock_realtime() \
57 __have_futex_clock_realtime = 1
59 #define __set_futex_clock_realtime() do { } while (0)
62 /* Version of the library, used in libthread_db to detect mismatches. */
63 static const char nptl_version[] __attribute_used__ = VERSION;
67 extern void __libc_setup_tls (size_t tcbsize, size_t tcbalign);
71 static void nptl_freeres (void);
74 static const struct pthread_functions pthread_functions =
76 .ptr_pthread_attr_destroy = __pthread_attr_destroy,
77 .ptr___pthread_attr_init_2_1 = __pthread_attr_init_2_1,
78 .ptr_pthread_attr_getdetachstate = __pthread_attr_getdetachstate,
79 .ptr_pthread_attr_setdetachstate = __pthread_attr_setdetachstate,
80 .ptr_pthread_attr_getinheritsched = __pthread_attr_getinheritsched,
81 .ptr_pthread_attr_setinheritsched = __pthread_attr_setinheritsched,
82 .ptr_pthread_attr_getschedparam = __pthread_attr_getschedparam,
83 .ptr_pthread_attr_setschedparam = __pthread_attr_setschedparam,
84 .ptr_pthread_attr_getschedpolicy = __pthread_attr_getschedpolicy,
85 .ptr_pthread_attr_setschedpolicy = __pthread_attr_setschedpolicy,
86 .ptr_pthread_attr_getscope = __pthread_attr_getscope,
87 .ptr_pthread_attr_setscope = __pthread_attr_setscope,
88 .ptr_pthread_condattr_destroy = __pthread_condattr_destroy,
89 .ptr_pthread_condattr_init = __pthread_condattr_init,
90 .ptr___pthread_cond_broadcast = __pthread_cond_broadcast,
91 .ptr___pthread_cond_destroy = __pthread_cond_destroy,
92 .ptr___pthread_cond_init = __pthread_cond_init,
93 .ptr___pthread_cond_signal = __pthread_cond_signal,
94 .ptr___pthread_cond_wait = __pthread_cond_wait,
95 .ptr___pthread_cond_timedwait = __pthread_cond_timedwait,
96 .ptr_pthread_equal = __pthread_equal,
97 .ptr___pthread_exit = __pthread_exit,
98 .ptr_pthread_getschedparam = __pthread_getschedparam,
99 .ptr_pthread_setschedparam = __pthread_setschedparam,
100 .ptr_pthread_mutex_destroy = INTUSE(__pthread_mutex_destroy),
101 .ptr_pthread_mutex_init = INTUSE(__pthread_mutex_init),
102 .ptr_pthread_mutex_lock = INTUSE(__pthread_mutex_lock),
103 .ptr_pthread_mutex_unlock = INTUSE(__pthread_mutex_unlock),
104 .ptr_pthread_self = __pthread_self,
105 .ptr_pthread_setcancelstate = __pthread_setcancelstate,
106 .ptr_pthread_setcanceltype = __pthread_setcanceltype,
107 .ptr___pthread_cleanup_upto = __pthread_cleanup_upto,
108 .ptr___pthread_once = __pthread_once_internal,
109 .ptr___pthread_rwlock_rdlock = __pthread_rwlock_rdlock_internal,
110 .ptr___pthread_rwlock_wrlock = __pthread_rwlock_wrlock_internal,
111 .ptr___pthread_rwlock_unlock = __pthread_rwlock_unlock_internal,
112 .ptr___pthread_key_create = __pthread_key_create_internal,
113 .ptr___pthread_getspecific = __pthread_getspecific_internal,
114 .ptr___pthread_setspecific = __pthread_setspecific_internal,
115 .ptr__pthread_cleanup_push_defer = _pthread_cleanup_push_defer,
116 .ptr__pthread_cleanup_pop_restore = _pthread_cleanup_pop_restore,
117 .ptr_nthreads = &__nptl_nthreads,
118 .ptr___pthread_unwind = &__pthread_unwind,
119 .ptr__nptl_deallocate_tsd = __nptl_deallocate_tsd,
120 .ptr__nptl_setxid = __nptl_setxid,
121 /* For now only the stack cache needs to be freed. */
122 .ptr_freeres = nptl_freeres
124 # define ptr_pthread_functions &pthread_functions
126 # define ptr_pthread_functions NULL
131 /* This function is called indirectly from the freeres code in libc. */
133 __libc_freeres_fn_section
142 /* For asynchronous cancellation we use a signal. This is the handler. */
144 sigcancel_handler (int sig, siginfo_t *si, void *ctx)
146 #ifdef __ASSUME_CORRECT_SI_PID
147 /* Determine the process ID. It might be negative if the thread is
148 in the middle of a fork() call. */
149 pid_t pid = THREAD_GETMEM (THREAD_SELF, pid);
150 if (__builtin_expect (pid < 0, 0))
154 /* Safety check. It would be possible to call this function for
155 other signals and send a signal from another process. This is not
156 correct and might even be a security problem. Try to catch as
157 many incorrect invocations as possible. */
159 #ifdef __ASSUME_CORRECT_SI_PID
160 /* Kernels before 2.5.75 stored the thread ID and not the process
161 ID in si_pid so we skip this test. */
164 || si->si_code != SI_TKILL)
167 struct pthread *self = THREAD_SELF;
169 int oldval = THREAD_GETMEM (self, cancelhandling);
172 /* We are canceled now. When canceled by another thread this flag
173 is already set but if the signal is directly send (internally or
174 from another process) is has to be done here. */
175 int newval = oldval | CANCELING_BITMASK | CANCELED_BITMASK;
177 if (oldval == newval || (oldval & EXITING_BITMASK) != 0)
178 /* Already canceled or exiting. */
181 int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval,
183 if (curval == oldval)
185 /* Set the return value. */
186 THREAD_SETMEM (self, result, PTHREAD_CANCELED);
188 /* Make sure asynchronous cancellation is still enabled. */
189 if ((newval & CANCELTYPE_BITMASK) != 0)
190 /* Run the registered destructors and terminate the thread. */
201 struct xid_command *__xidcmd attribute_hidden;
203 /* For asynchronous cancellation we use a signal. This is the handler. */
205 sighandler_setxid (int sig, siginfo_t *si, void *ctx)
207 #ifdef __ASSUME_CORRECT_SI_PID
208 /* Determine the process ID. It might be negative if the thread is
209 in the middle of a fork() call. */
210 pid_t pid = THREAD_GETMEM (THREAD_SELF, pid);
211 if (__builtin_expect (pid < 0, 0))
215 /* Safety check. It would be possible to call this function for
216 other signals and send a signal from another process. This is not
217 correct and might even be a security problem. Try to catch as
218 many incorrect invocations as possible. */
220 #ifdef __ASSUME_CORRECT_SI_PID
221 /* Kernels before 2.5.75 stored the thread ID and not the process
222 ID in si_pid so we skip this test. */
225 || si->si_code != SI_TKILL)
228 INTERNAL_SYSCALL_DECL (err);
229 INTERNAL_SYSCALL_NCS (__xidcmd->syscall_no, err, 3, __xidcmd->id[0],
230 __xidcmd->id[1], __xidcmd->id[2]);
232 /* Reset the SETXID flag. */
233 struct pthread *self = THREAD_SELF;
237 flags = THREAD_GETMEM (self, cancelhandling);
238 newval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling,
239 flags & ~SETXID_BITMASK, flags);
241 while (flags != newval);
243 /* And release the futex. */
244 self->setxid_futex = 1;
245 lll_futex_wake (&self->setxid_futex, 1, LLL_PRIVATE);
247 if (atomic_decrement_val (&__xidcmd->cntr) == 0)
248 lll_futex_wake (&__xidcmd->cntr, 1, LLL_PRIVATE);
252 /* When using __thread for this, we do it in libc so as not
253 to give libpthread its own TLS segment just for this. */
254 extern void **__libc_dl_error_tsd (void) __attribute__ ((const));
257 /* This can be set by the debugger before initialization is complete. */
258 static bool __nptl_initial_report_events __attribute_used__;
260 void __pthread_initialize_minimal_internal (void) attribute_hidden;
262 __pthread_initialize_minimal_internal (void)
264 static int initialized = 0;
271 /* Unlike in the dynamically linked case the dynamic linker has not
272 taken care of initializing the TLS data structures. */
273 __libc_setup_tls (TLS_TCB_SIZE, TLS_TCB_ALIGN);
275 /* We must prevent gcc from being clever and move any of the
276 following code ahead of the __libc_setup_tls call. This function
277 will initialize the thread register which is subsequently
279 __asm__ __volatile__ ("");
282 /* Minimal initialization of the thread descriptor. */
283 struct pthread *pd = THREAD_SELF;
284 INTERNAL_SYSCALL_DECL (err);
285 pd->pid = pd->tid = INTERNAL_SYSCALL (set_tid_address, err, 1, &pd->tid);
286 THREAD_SETMEM (pd, specific[0], &pd->specific_1stblock[0]);
287 THREAD_SETMEM (pd, user_stack, true);
288 if (LLL_LOCK_INITIALIZER != 0)
289 THREAD_SETMEM (pd, lock, LLL_LOCK_INITIALIZER);
291 THREAD_SETMEM (pd, cpuclock_offset, GL(dl_cpuclock_offset));
294 /* Initialize the robust mutex data. */
295 #ifdef __PTHREAD_MUTEX_HAVE_PREV
296 pd->robust_prev = &pd->robust_head;
298 pd->robust_head.list = &pd->robust_head;
299 #ifdef __NR_set_robust_list
300 pd->robust_head.futex_offset = (offsetof (pthread_mutex_t, __data.__lock)
301 - offsetof (pthread_mutex_t,
302 __data.__list.__next));
303 int res = INTERNAL_SYSCALL (set_robust_list, err, 2, &pd->robust_head,
304 sizeof (struct robust_list_head));
305 if (INTERNAL_SYSCALL_ERROR_P (res, err))
307 set_robust_list_not_avail ();
309 #ifndef __ASSUME_PRIVATE_FUTEX
310 /* Private futexes are always used (at least internally) so that
311 doing the test once this early is beneficial. */
314 word = INTERNAL_SYSCALL (futex, err, 3, &word,
315 FUTEX_WAKE | FUTEX_PRIVATE_FLAG, 1);
316 if (!INTERNAL_SYSCALL_ERROR_P (word, err))
317 THREAD_SETMEM (pd, header.private_futex, FUTEX_PRIVATE_FLAG);
320 /* Private futexes have been introduced earlier than the
321 FUTEX_CLOCK_REALTIME flag. We don't have to run the test if we
322 know the former are not supported. This also means we know the
323 kernel will return ENOSYS for unknown operations. */
324 if (THREAD_GETMEM (pd, header.private_futex) != 0)
326 #ifndef __ASSUME_FUTEX_CLOCK_REALTIME
329 /* NB: the syscall actually takes six parameters. The last is the
330 bit mask. But since we will not actually wait at all the value
331 is irrelevant. Given that passing six parameters is difficult
332 on some architectures we just pass whatever random value the
333 calling convention calls for to the kernel. It causes no harm. */
334 word = INTERNAL_SYSCALL (futex, err, 5, &word,
335 FUTEX_WAIT_BITSET | FUTEX_CLOCK_REALTIME
336 | FUTEX_PRIVATE_FLAG, 1, NULL, 0);
337 assert (INTERNAL_SYSCALL_ERROR_P (word, err));
338 if (INTERNAL_SYSCALL_ERRNO (word, err) != ENOSYS)
339 __set_futex_clock_realtime ();
343 /* Set initial thread's stack block from 0 up to __libc_stack_end.
344 It will be bigger than it actually is, but for unwind.c/pt-longjmp.c
345 purposes this is good enough. */
346 THREAD_SETMEM (pd, stackblock_size, (size_t) __libc_stack_end);
348 /* Initialize the list of all running threads with the main thread. */
349 INIT_LIST_HEAD (&__stack_user);
350 list_add (&pd->list, &__stack_user);
352 /* Before initializing __stack_user, the debugger could not find us and
353 had to set __nptl_initial_report_events. Propagate its setting. */
354 THREAD_SETMEM (pd, report_events, __nptl_initial_report_events);
356 /* Install the cancellation signal handler. If for some reason we
357 cannot install the handler we do not abort. Maybe we should, but
358 it is only asynchronous cancellation which is affected. */
360 sa.sa_sigaction = sigcancel_handler;
361 sa.sa_flags = SA_SIGINFO;
362 __sigemptyset (&sa.sa_mask);
364 (void) __libc_sigaction (SIGCANCEL, &sa, NULL);
366 /* Install the handle to change the threads' uid/gid. */
367 sa.sa_sigaction = sighandler_setxid;
368 sa.sa_flags = SA_SIGINFO | SA_RESTART;
370 (void) __libc_sigaction (SIGSETXID, &sa, NULL);
372 /* The parent process might have left the signals blocked. Just in
373 case, unblock it. We reuse the signal mask in the sigaction
374 structure. It is already cleared. */
375 __sigaddset (&sa.sa_mask, SIGCANCEL);
376 __sigaddset (&sa.sa_mask, SIGSETXID);
377 (void) INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_UNBLOCK, &sa.sa_mask,
380 /* Get the size of the static and alignment requirements for the TLS
382 size_t static_tls_align;
383 _dl_get_tls_static_info (&__static_tls_size, &static_tls_align);
385 /* Make sure the size takes all the alignments into account. */
386 if (STACK_ALIGN > static_tls_align)
387 static_tls_align = STACK_ALIGN;
388 __static_tls_align_m1 = static_tls_align - 1;
390 __static_tls_size = roundup (__static_tls_size, static_tls_align);
392 /* Determine the default allowed stack size. This is the size used
393 in case the user does not specify one. */
395 if (getrlimit (RLIMIT_STACK, &limit) != 0
396 || limit.rlim_cur == RLIM_INFINITY)
397 /* The system limit is not usable. Use an architecture-specific
399 limit.rlim_cur = ARCH_STACK_DEFAULT_SIZE;
400 else if (limit.rlim_cur < PTHREAD_STACK_MIN)
401 /* The system limit is unusably small.
402 Use the minimal size acceptable. */
403 limit.rlim_cur = PTHREAD_STACK_MIN;
405 /* Make sure it meets the minimum size that allocate_stack
406 (allocatestack.c) will demand, which depends on the page size. */
407 const uintptr_t pagesz = sysconf (_SC_PAGESIZE);
408 const size_t minstack = pagesz + __static_tls_size + MINIMAL_REST_STACK;
409 if (limit.rlim_cur < minstack)
410 limit.rlim_cur = minstack;
412 /* Round the resource limit up to page size. */
413 limit.rlim_cur = (limit.rlim_cur + pagesz - 1) & -pagesz;
414 __default_stacksize = limit.rlim_cur;
417 /* Transfer the old value from the dynamic linker's internal location. */
418 *__libc_dl_error_tsd () = *(*GL(dl_error_catch_tsd)) ();
419 GL(dl_error_catch_tsd) = &__libc_dl_error_tsd;
423 GL(dl_init_static_tls) = &__pthread_init_static_tls;
425 /* Register the fork generation counter with the libc. */
426 #ifndef TLS_MULTIPLE_THREADS_IN_TCB
427 __libc_multiple_threads_ptr =
429 __libc_pthread_init (&__fork_generation, __reclaim_stacks,
430 ptr_pthread_functions);
432 /* Determine whether the machine is SMP or not. */
433 __is_smp = is_smp_system ();
435 /* uClibc-specific stdio initialization for threads. */
438 _stdio_user_locking = 0; /* 2 if threading not initialized */
439 for (fp = _stdio_openlist; fp != NULL; fp = fp->__nextopen) {
440 if (fp->__user_locking != 1) {
441 fp->__user_locking = 0;
446 strong_alias (__pthread_initialize_minimal_internal,
447 __pthread_initialize_minimal)