1 /* Copyright (C) 2002,2003,2004,2005,2006,2007 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
27 #include <sys/param.h>
28 #include <dl-sysdep.h>
30 #include <lowlevellock.h>
33 #ifndef NEED_SEPARATE_REGISTER_STACK
35 /* Most architectures have exactly one stack pointer. Some have more. */
36 # define STACK_VARIABLES void *stackaddr = NULL
38 /* How to pass the values to the 'create_thread' function. */
39 # define STACK_VARIABLES_ARGS stackaddr
41 /* How to declare function which gets there parameters. */
42 # define STACK_VARIABLES_PARMS void *stackaddr
44 /* How to declare allocate_stack. */
45 # define ALLOCATE_STACK_PARMS void **stack
47 /* This is how the function is called. We do it this way to allow
48 other variants of the function to have more parameters. */
49 # define ALLOCATE_STACK(attr, pd) allocate_stack (attr, pd, &stackaddr)
53 /* We need two stacks. The kernel will place them but we have to tell
54 the kernel about the size of the reserved address space. */
55 # define STACK_VARIABLES void *stackaddr = NULL; size_t stacksize = 0
57 /* How to pass the values to the 'create_thread' function. */
58 # define STACK_VARIABLES_ARGS stackaddr, stacksize
60 /* How to declare function which gets there parameters. */
61 # define STACK_VARIABLES_PARMS void *stackaddr, size_t stacksize
63 /* How to declare allocate_stack. */
64 # define ALLOCATE_STACK_PARMS void **stack, size_t *stacksize
66 /* This is how the function is called. We do it this way to allow
67 other variants of the function to have more parameters. */
68 # define ALLOCATE_STACK(attr, pd) \
69 allocate_stack (attr, pd, &stackaddr, &stacksize)
74 /* Default alignment of stack. */
76 # define STACK_ALIGN __alignof__ (long double)
79 /* Default value for minimal stack size after allocating thread
80 descriptor and guard. */
81 #ifndef MINIMAL_REST_STACK
82 # define MINIMAL_REST_STACK 4096
86 /* Let the architecture add some flags to the mmap() call used to
88 #ifndef ARCH_MAP_FLAGS
89 # define ARCH_MAP_FLAGS 0
92 /* This yields the pointer that TLS support code calls the thread pointer. */
94 # define TLS_TPADJ(pd) (pd)
96 # define TLS_TPADJ(pd) ((struct pthread *)((char *) (pd) + TLS_PRE_TCB_SIZE))
99 /* Cache handling for not-yet free stacks. */
101 /* Maximum size in kB of cache. */
102 static size_t stack_cache_maxsize
= 40 * 1024 * 1024; /* 40MiBi by default. */
103 static size_t stack_cache_actsize
;
105 /* Mutex protecting this variable. */
106 static lll_lock_t stack_cache_lock
= LLL_LOCK_INITIALIZER
;
108 /* List of queued stack frames. */
109 static LIST_HEAD (stack_cache
);
111 /* List of the stacks in use. */
112 static LIST_HEAD (stack_used
);
114 /* List of the threads with user provided stacks in use. No need to
115 initialize this, since it's done in __pthread_initialize_minimal. */
116 list_t __stack_user
__attribute__ ((nocommon
));
117 hidden_data_def (__stack_user
)
119 #if COLORING_INCREMENT != 0
120 /* Number of threads created. */
121 static unsigned int nptl_ncreated
;
125 /* Check whether the stack is still used or not. */
126 #define FREE_P(descr) ((descr)->tid <= 0)
129 /* We create a double linked list of all cache entries. Double linked
130 because this allows removing entries from the end. */
133 /* Get a stack frame from the cache. We have to match by size since
134 some blocks might be too small or far too large. */
135 static struct pthread
*
136 get_cached_stack (size_t *sizep
, void **memp
)
138 size_t size
= *sizep
;
139 struct pthread
*result
= NULL
;
142 lll_lock (stack_cache_lock
);
144 /* Search the cache for a matching entry. We search for the
145 smallest stack which has at least the required size. Note that
146 in normal situations the size of all allocated stacks is the
147 same. As the very least there are only a few different sizes.
148 Therefore this loop will exit early most of the time with an
150 list_for_each (entry
, &stack_cache
)
152 struct pthread
*curr
;
154 curr
= list_entry (entry
, struct pthread
, list
);
155 if (FREE_P (curr
) && curr
->stackblock_size
>= size
)
157 if (curr
->stackblock_size
== size
)
164 || result
->stackblock_size
> curr
->stackblock_size
)
169 if (__builtin_expect (result
== NULL
, 0)
170 /* Make sure the size difference is not too excessive. In that
171 case we do not use the block. */
172 || __builtin_expect (result
->stackblock_size
> 4 * size
, 0))
174 /* Release the lock. */
175 lll_unlock (stack_cache_lock
);
180 /* Dequeue the entry. */
181 list_del (&result
->list
);
183 /* And add to the list of stacks in use. */
184 list_add (&result
->list
, &stack_used
);
186 /* And decrease the cache size. */
187 stack_cache_actsize
-= result
->stackblock_size
;
189 /* Release the lock early. */
190 lll_unlock (stack_cache_lock
);
192 /* Report size and location of the stack to the caller. */
193 *sizep
= result
->stackblock_size
;
194 *memp
= result
->stackblock
;
196 /* Cancellation handling is back to the default. */
197 result
->cancelhandling
= 0;
198 result
->cleanup
= NULL
;
200 /* No pending event. */
201 result
->nextevent
= NULL
;
204 dtv_t
*dtv
= GET_DTV (TLS_TPADJ (result
));
205 memset (dtv
, '\0', (dtv
[-1].counter
+ 1) * sizeof (dtv_t
));
207 /* Re-initialize the TLS. */
208 _dl_allocate_tls_init (TLS_TPADJ (result
));
214 /* Free stacks until cache size is lower than LIMIT. */
216 free_stacks (size_t limit
)
218 /* We reduce the size of the cache. Remove the last entries until
219 the size is below the limit. */
223 /* Search from the end of the list. */
224 list_for_each_prev_safe (entry
, prev
, &stack_cache
)
226 struct pthread
*curr
;
228 curr
= list_entry (entry
, struct pthread
, list
);
231 /* Unlink the block. */
234 /* Account for the freed memory. */
235 stack_cache_actsize
-= curr
->stackblock_size
;
237 /* Free the memory associated with the ELF TLS. */
238 _dl_deallocate_tls (TLS_TPADJ (curr
), false);
240 /* Remove this block. This should never fail. If it does
241 something is really wrong. */
242 if (munmap (curr
->stackblock
, curr
->stackblock_size
) != 0)
245 /* Maybe we have freed enough. */
246 if (stack_cache_actsize
<= limit
)
253 /* Add a stack frame which is not used anymore to the stack. Must be
254 called with the cache lock held. */
256 __attribute ((always_inline
))
257 queue_stack (struct pthread
*stack
)
259 /* We unconditionally add the stack to the list. The memory may
260 still be in use but it will not be reused until the kernel marks
261 the stack as not used anymore. */
262 list_add (&stack
->list
, &stack_cache
);
264 stack_cache_actsize
+= stack
->stackblock_size
;
265 if (__builtin_expect (stack_cache_actsize
> stack_cache_maxsize
, 0))
266 free_stacks (stack_cache_maxsize
);
270 /* This function is called indirectly from the freeres code in libc. */
272 __free_stack_cache (void)
280 change_stack_perm (struct pthread
*pd
281 #ifdef NEED_SEPARATE_REGISTER_STACK
286 #ifdef NEED_SEPARATE_REGISTER_STACK
287 void *stack
= (pd
->stackblock
288 + (((((pd
->stackblock_size
- pd
->guardsize
) / 2)
289 & pagemask
) + pd
->guardsize
) & pagemask
));
290 size_t len
= pd
->stackblock
+ pd
->stackblock_size
- stack
;
291 #elif _STACK_GROWS_DOWN
292 void *stack
= pd
->stackblock
+ pd
->guardsize
;
293 size_t len
= pd
->stackblock_size
- pd
->guardsize
;
294 #elif _STACK_GROWS_UP
295 void *stack
= pd
->stackblock
;
296 size_t len
= (uintptr_t) pd
- pd
->guardsize
- (uintptr_t) pd
->stackblock
;
298 # error "Define either _STACK_GROWS_DOWN or _STACK_GROWS_UP"
300 if (mprotect (stack
, len
, PROT_READ
| PROT_WRITE
| PROT_EXEC
) != 0)
308 allocate_stack (const struct pthread_attr
*attr
, struct pthread
**pdp
,
309 ALLOCATE_STACK_PARMS
)
313 size_t pagesize_m1
= __getpagesize () - 1;
316 assert (attr
!= NULL
);
317 assert (powerof2 (pagesize_m1
+ 1));
318 assert (TCB_ALIGNMENT
>= STACK_ALIGN
);
320 /* Get the stack size from the attribute if it is set. Otherwise we
321 use the default we determined at start time. */
322 size
= attr
->stacksize
?: __default_stacksize
;
324 /* Get memory for the stack. */
325 if (__builtin_expect (attr
->flags
& ATTR_FLAG_STACKADDR
, 0))
329 /* If the user also specified the size of the stack make sure it
331 if (attr
->stacksize
!= 0
332 && attr
->stacksize
< (__static_tls_size
+ MINIMAL_REST_STACK
))
335 /* Adjust stack size for alignment of the TLS block. */
337 adj
= ((uintptr_t) attr
->stackaddr
- TLS_TCB_SIZE
)
338 & __static_tls_align_m1
;
339 assert (size
> adj
+ TLS_TCB_SIZE
);
341 adj
= ((uintptr_t) attr
->stackaddr
- __static_tls_size
)
342 & __static_tls_align_m1
;
346 /* The user provided some memory. Let's hope it matches the
347 size... We do not allocate guard pages if the user provided
348 the stack. It is the user's responsibility to do this if it
351 pd
= (struct pthread
*) ((uintptr_t) attr
->stackaddr
352 - TLS_TCB_SIZE
- adj
);
354 pd
= (struct pthread
*) (((uintptr_t) attr
->stackaddr
355 - __static_tls_size
- adj
)
359 /* The user provided stack memory needs to be cleared. */
360 memset (pd
, '\0', sizeof (struct pthread
));
362 /* The first TSD block is included in the TCB. */
363 pd
->specific
[0] = pd
->specific_1stblock
;
365 /* Remember the stack-related values. */
366 pd
->stackblock
= (char *) attr
->stackaddr
- size
;
367 pd
->stackblock_size
= size
;
369 /* This is a user-provided stack. It will not be queued in the
370 stack cache nor will the memory (except the TLS memory) be freed. */
371 pd
->user_stack
= true;
373 /* This is at least the second thread. */
374 pd
->header
.multiple_threads
= 1;
375 #ifndef TLS_MULTIPLE_THREADS_IN_TCB
376 __pthread_multiple_threads
= *__libc_multiple_threads_ptr
= 1;
379 #ifndef __ASSUME_PRIVATE_FUTEX
380 /* The thread must know when private futexes are supported. */
381 pd
->header
.private_futex
= THREAD_GETMEM (THREAD_SELF
,
382 header
.private_futex
);
385 #ifdef NEED_DL_SYSINFO
386 /* Copy the sysinfo value from the parent. */
387 THREAD_SYSINFO(pd
) = THREAD_SELF_SYSINFO
;
390 /* The process ID is also the same as that of the caller. */
391 pd
->pid
= THREAD_GETMEM (THREAD_SELF
, pid
);
393 /* Allocate the DTV for this thread. */
394 if (_dl_allocate_tls (TLS_TPADJ (pd
)) == NULL
)
396 /* Something went wrong. */
397 assert (errno
== ENOMEM
);
402 /* Prepare to modify global data. */
403 lll_lock (stack_cache_lock
);
405 /* And add to the list of stacks in use. */
406 list_add (&pd
->list
, &__stack_user
);
408 lll_unlock (stack_cache_lock
);
412 /* Allocate some anonymous memory. If possible use the cache. */
416 const int prot
= (PROT_READ
| PROT_WRITE
417 | ((GL(dl_stack_flags
) & PF_X
) ? PROT_EXEC
: 0));
419 #if COLORING_INCREMENT != 0
420 /* Add one more page for stack coloring. Don't do it for stacks
421 with 16 times pagesize or larger. This might just cause
422 unnecessary misalignment. */
423 if (size
<= 16 * pagesize_m1
)
424 size
+= pagesize_m1
+ 1;
427 /* Adjust the stack size for alignment. */
428 size
&= ~__static_tls_align_m1
;
431 /* Make sure the size of the stack is enough for the guard and
432 eventually the thread descriptor. */
433 guardsize
= (attr
->guardsize
+ pagesize_m1
) & ~pagesize_m1
;
434 if (__builtin_expect (size
< ((guardsize
+ __static_tls_size
435 + MINIMAL_REST_STACK
+ pagesize_m1
)
438 /* The stack is too small (or the guard too large). */
441 /* Try to get a stack from the cache. */
443 pd
= get_cached_stack (&size
, &mem
);
446 /* To avoid aliasing effects on a larger scale than pages we
447 adjust the allocated stack size if necessary. This way
448 allocations directly following each other will not have
449 aliasing problems. */
450 #if MULTI_PAGE_ALIASING != 0
451 if ((size
% MULTI_PAGE_ALIASING
) == 0)
452 size
+= pagesize_m1
+ 1;
455 mem
= mmap (NULL
, size
, prot
,
456 MAP_PRIVATE
| MAP_ANONYMOUS
| ARCH_MAP_FLAGS
, -1, 0);
458 if (__builtin_expect (mem
== MAP_FAILED
, 0))
460 #ifdef ARCH_RETRY_MMAP
461 mem
= ARCH_RETRY_MMAP (size
);
462 if (__builtin_expect (mem
== MAP_FAILED
, 0))
467 /* SIZE is guaranteed to be greater than zero.
468 So we can never get a null pointer back from mmap. */
469 assert (mem
!= NULL
);
471 #if COLORING_INCREMENT != 0
472 /* Atomically increment NCREATED. */
473 unsigned int ncreated
= atomic_increment_val (&nptl_ncreated
);
475 /* We chose the offset for coloring by incrementing it for
476 every new thread by a fixed amount. The offset used
477 module the page size. Even if coloring would be better
478 relative to higher alignment values it makes no sense to
479 do it since the mmap() interface does not allow us to
480 specify any alignment for the returned memory block. */
481 size_t coloring
= (ncreated
* COLORING_INCREMENT
) & pagesize_m1
;
483 /* Make sure the coloring offsets does not disturb the alignment
484 of the TCB and static TLS block. */
485 if (__builtin_expect ((coloring
& __static_tls_align_m1
) != 0, 0))
486 coloring
= (((coloring
+ __static_tls_align_m1
)
487 & ~(__static_tls_align_m1
))
490 /* Unless specified we do not make any adjustments. */
494 /* Place the thread descriptor at the end of the stack. */
496 pd
= (struct pthread
*) ((char *) mem
+ size
- coloring
) - 1;
498 pd
= (struct pthread
*) ((((uintptr_t) mem
+ size
- coloring
500 & ~__static_tls_align_m1
)
504 /* Remember the stack-related values. */
505 pd
->stackblock
= mem
;
506 pd
->stackblock_size
= size
;
508 /* We allocated the first block thread-specific data array.
509 This address will not change for the lifetime of this
511 pd
->specific
[0] = pd
->specific_1stblock
;
513 /* This is at least the second thread. */
514 pd
->header
.multiple_threads
= 1;
515 #ifndef TLS_MULTIPLE_THREADS_IN_TCB
516 __pthread_multiple_threads
= *__libc_multiple_threads_ptr
= 1;
519 /* The thread must know when private futexes are supported. */
520 pd
->header
.private_futex
= THREAD_GETMEM (THREAD_SELF
,
521 header
.private_futex
);
523 #ifdef NEED_DL_SYSINFO
524 /* Copy the sysinfo value from the parent. */
525 THREAD_SYSINFO(pd
) = THREAD_SELF_SYSINFO
;
528 /* The process ID is also the same as that of the caller. */
529 pd
->pid
= THREAD_GETMEM (THREAD_SELF
, pid
);
531 /* Allocate the DTV for this thread. */
532 if (_dl_allocate_tls (TLS_TPADJ (pd
)) == NULL
)
534 /* Something went wrong. */
535 assert (errno
== ENOMEM
);
537 /* Free the stack memory we just allocated. */
538 (void) munmap (mem
, size
);
544 /* Prepare to modify global data. */
545 lll_lock (stack_cache_lock
);
547 /* And add to the list of stacks in use. */
548 list_add (&pd
->list
, &stack_used
);
550 lll_unlock (stack_cache_lock
);
553 /* There might have been a race. Another thread might have
554 caused the stacks to get exec permission while this new
555 stack was prepared. Detect if this was possible and
556 change the permission if necessary. */
557 if (__builtin_expect ((GL(dl_stack_flags
) & PF_X
) != 0
558 && (prot
& PROT_EXEC
) == 0, 0))
560 int err
= change_stack_perm (pd
561 #ifdef NEED_SEPARATE_REGISTER_STACK
567 /* Free the stack memory we just allocated. */
568 (void) munmap (mem
, size
);
575 /* Note that all of the stack and the thread descriptor is
576 zeroed. This means we do not have to initialize fields
577 with initial value zero. This is specifically true for
578 the 'tid' field which is always set back to zero once the
579 stack is not used anymore and for the 'guardsize' field
580 which will be read next. */
583 /* Create or resize the guard area if necessary. */
584 if (__builtin_expect (guardsize
> pd
->guardsize
, 0))
586 #ifdef NEED_SEPARATE_REGISTER_STACK
587 char *guard
= mem
+ (((size
- guardsize
) / 2) & ~pagesize_m1
);
588 #elif _STACK_GROWS_DOWN
590 # elif _STACK_GROWS_UP
591 char *guard
= (char *) (((uintptr_t) pd
- guardsize
) & ~pagesize_m1
);
593 if (mprotect (guard
, guardsize
, PROT_NONE
) != 0)
599 lll_lock (stack_cache_lock
);
601 /* Remove the thread from the list. */
602 list_del (&pd
->list
);
604 lll_unlock (stack_cache_lock
);
606 /* Get rid of the TLS block we allocated. */
607 _dl_deallocate_tls (TLS_TPADJ (pd
), false);
609 /* Free the stack memory regardless of whether the size
610 of the cache is over the limit or not. If this piece
611 of memory caused problems we better do not use it
612 anymore. Uh, and we ignore possible errors. There
613 is nothing we could do. */
614 (void) munmap (mem
, size
);
619 pd
->guardsize
= guardsize
;
621 else if (__builtin_expect (pd
->guardsize
- guardsize
> size
- reqsize
,
624 /* The old guard area is too large. */
626 #ifdef NEED_SEPARATE_REGISTER_STACK
627 char *guard
= mem
+ (((size
- guardsize
) / 2) & ~pagesize_m1
);
628 char *oldguard
= mem
+ (((size
- pd
->guardsize
) / 2) & ~pagesize_m1
);
631 && mprotect (oldguard
, guard
- oldguard
, prot
) != 0)
634 if (mprotect (guard
+ guardsize
,
635 oldguard
+ pd
->guardsize
- guard
- guardsize
,
638 #elif _STACK_GROWS_DOWN
639 if (mprotect ((char *) mem
+ guardsize
, pd
->guardsize
- guardsize
,
642 #elif _STACK_GROWS_UP
643 if (mprotect ((char *) pd
- pd
->guardsize
,
644 pd
->guardsize
- guardsize
, prot
) != 0)
648 pd
->guardsize
= guardsize
;
650 /* The pthread_getattr_np() calls need to get passed the size
651 requested in the attribute, regardless of how large the
652 actually used guardsize is. */
653 pd
->reported_guardsize
= guardsize
;
656 /* Initialize the lock. We have to do this unconditionally since the
657 stillborn thread could be canceled while the lock is taken. */
658 pd
->lock
= LLL_LOCK_INITIALIZER
;
660 /* The robust mutex lists also need to be initialized
661 unconditionally because the cleanup for the previous stack owner
662 might have happened in the kernel. */
663 pd
->robust_head
.futex_offset
= (offsetof (pthread_mutex_t
, __data
.__lock
)
664 - offsetof (pthread_mutex_t
,
665 __data
.__list
.__next
));
666 pd
->robust_head
.list_op_pending
= NULL
;
667 #ifdef __PTHREAD_MUTEX_HAVE_PREV
668 pd
->robust_prev
= &pd
->robust_head
;
670 pd
->robust_head
.list
= &pd
->robust_head
;
672 /* We place the thread descriptor at the end of the stack. */
676 /* The stack begins before the TCB and the static TLS block. */
677 stacktop
= ((char *) (pd
+ 1) - __static_tls_size
);
679 stacktop
= (char *) (pd
- 1);
682 #ifdef NEED_SEPARATE_REGISTER_STACK
683 *stack
= pd
->stackblock
;
684 *stacksize
= stacktop
- *stack
;
685 #elif _STACK_GROWS_DOWN
687 #elif _STACK_GROWS_UP
688 *stack
= pd
->stackblock
;
698 __deallocate_stack (struct pthread
*pd
)
700 lll_lock (stack_cache_lock
);
702 /* Remove the thread from the list of threads with user defined
704 list_del (&pd
->list
);
706 /* Not much to do. Just free the mmap()ed memory. Note that we do
707 not reset the 'used' flag in the 'tid' field. This is done by
708 the kernel. If no thread has been created yet this field is
710 if (__builtin_expect (! pd
->user_stack
, 1))
711 (void) queue_stack (pd
);
713 /* Free the memory associated with the ELF TLS. */
714 _dl_deallocate_tls (TLS_TPADJ (pd
), false);
716 lll_unlock (stack_cache_lock
);
722 __make_stacks_executable (void **stack_endp
)
724 /* First the main thread's stack. */
725 int err
= _dl_make_stack_executable (stack_endp
);
729 #ifdef NEED_SEPARATE_REGISTER_STACK
730 const size_t pagemask
= ~(__getpagesize () - 1);
733 lll_lock (stack_cache_lock
);
736 list_for_each (runp
, &stack_used
)
738 err
= change_stack_perm (list_entry (runp
, struct pthread
, list
)
739 #ifdef NEED_SEPARATE_REGISTER_STACK
747 /* Also change the permission for the currently unused stacks. This
748 might be wasted time but better spend it here than adding a check
751 list_for_each (runp
, &stack_cache
)
753 err
= change_stack_perm (list_entry (runp
, struct pthread
, list
)
754 #ifdef NEED_SEPARATE_REGISTER_STACK
762 lll_unlock (stack_cache_lock
);
768 /* In case of a fork() call the memory allocation in the child will be
769 the same but only one thread is running. All stacks except that of
770 the one running thread are not used anymore. We have to recycle
773 __reclaim_stacks (void)
775 struct pthread
*self
= (struct pthread
*) THREAD_SELF
;
777 /* No locking necessary. The caller is the only stack in use. */
779 /* Mark all stacks except the still running one as free. */
781 list_for_each (runp
, &stack_used
)
783 struct pthread
*curp
= list_entry (runp
, struct pthread
, list
);
786 /* This marks the stack as free. */
789 /* The PID field must be initialized for the new process. */
790 curp
->pid
= self
->pid
;
792 /* Account for the size of the stack. */
793 stack_cache_actsize
+= curp
->stackblock_size
;
797 /* Reset the PIDs in any cached stacks. */
798 list_for_each (runp
, &stack_cache
)
800 struct pthread
*curp
= list_entry (runp
, struct pthread
, list
);
801 curp
->pid
= self
->pid
;
804 /* Add the stack of all running threads to the cache. */
805 list_splice (&stack_used
, &stack_cache
);
807 /* Remove the entry for the current thread to from the cache list
808 and add it to the list of running threads. Which of the two
809 lists is decided by the user_stack flag. */
810 list_del (&self
->list
);
812 /* Re-initialize the lists for all the threads. */
813 INIT_LIST_HEAD (&stack_used
);
814 INIT_LIST_HEAD (&__stack_user
);
816 if (__builtin_expect (THREAD_GETMEM (self
, user_stack
), 0))
817 list_add (&self
->list
, &__stack_user
);
819 list_add (&self
->list
, &stack_used
);
821 /* There is one thread running. */
824 /* Initialize the lock. */
825 stack_cache_lock
= LLL_LOCK_INITIALIZER
;
830 # undef __find_thread_by_id
831 /* Find a thread given the thread ID. */
834 __find_thread_by_id (pid_t tid
)
836 struct pthread
*result
= NULL
;
838 lll_lock (stack_cache_lock
);
840 /* Iterate over the list with system-allocated threads first. */
842 list_for_each (runp
, &stack_used
)
844 struct pthread
*curp
;
846 curp
= list_entry (runp
, struct pthread
, list
);
848 if (curp
->tid
== tid
)
855 /* Now the list with threads using user-allocated stacks. */
856 list_for_each (runp
, &__stack_user
)
858 struct pthread
*curp
;
860 curp
= list_entry (runp
, struct pthread
, list
);
862 if (curp
->tid
== tid
)
870 lll_unlock (stack_cache_lock
);
879 setxid_signal_thread (struct xid_command
*cmdp
, struct pthread
*t
)
881 if (! IS_DETACHED (t
))
886 ch
= t
->cancelhandling
;
888 /* If the thread is exiting right now, ignore it. */
889 if ((ch
& EXITING_BITMASK
) != 0)
892 while (atomic_compare_and_exchange_bool_acq (&t
->cancelhandling
,
893 ch
| SETXID_BITMASK
, ch
));
897 INTERNAL_SYSCALL_DECL (err
);
899 val
= INTERNAL_SYSCALL (tgkill
, err
, 3, THREAD_GETMEM (THREAD_SELF
, pid
),
903 val
= INTERNAL_SYSCALL (tgkill
, err
, 3, THREAD_GETMEM (THREAD_SELF
, pid
),
905 if (INTERNAL_SYSCALL_ERROR_P (val
, err
)
906 && INTERNAL_SYSCALL_ERRNO (val
, err
) == ENOSYS
)
908 val
= INTERNAL_SYSCALL (tkill
, err
, 2, t
->tid
, SIGSETXID
);
911 if (!INTERNAL_SYSCALL_ERROR_P (val
, err
))
912 atomic_increment (&cmdp
->cntr
);
918 __nptl_setxid (struct xid_command
*cmdp
)
921 lll_lock (stack_cache_lock
);
926 struct pthread
*self
= THREAD_SELF
;
928 /* Iterate over the list with system-allocated threads first. */
930 list_for_each (runp
, &stack_used
)
932 struct pthread
*t
= list_entry (runp
, struct pthread
, list
);
936 setxid_signal_thread (cmdp
, t
);
939 /* Now the list with threads using user-allocated stacks. */
940 list_for_each (runp
, &__stack_user
)
942 struct pthread
*t
= list_entry (runp
, struct pthread
, list
);
946 setxid_signal_thread (cmdp
, t
);
949 int cur
= cmdp
->cntr
;
952 lll_private_futex_wait (&cmdp
->cntr
, cur
);
956 /* This must be last, otherwise the current thread might not have
957 permissions to send SIGSETXID syscall to the other threads. */
958 INTERNAL_SYSCALL_DECL (err
);
959 result
= INTERNAL_SYSCALL_NCS (cmdp
->syscall_no
, err
, 3,
960 cmdp
->id
[0], cmdp
->id
[1], cmdp
->id
[2]);
961 if (INTERNAL_SYSCALL_ERROR_P (result
, err
))
963 __set_errno (INTERNAL_SYSCALL_ERRNO (result
, err
));
967 lll_unlock (stack_cache_lock
);
971 static inline void __attribute__((always_inline
))
972 init_one_static_tls (struct pthread
*curp
, struct link_map
*map
)
974 dtv_t
*dtv
= GET_DTV (TLS_TPADJ (curp
));
976 void *dest
= (char *) curp
- map
->l_tls_offset
;
978 void *dest
= (char *) curp
+ map
->l_tls_offset
+ TLS_PRE_TCB_SIZE
;
980 # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
983 /* Fill in the DTV slot so that a later LD/GD access will find it. */
984 dtv
[map
->l_tls_modid
].pointer
.val
= dest
;
985 dtv
[map
->l_tls_modid
].pointer
.is_static
= true;
987 /* Initialize the memory. */
988 memset (__mempcpy (dest
, map
->l_tls_initimage
, map
->l_tls_initimage_size
),
989 '\0', map
->l_tls_blocksize
- map
->l_tls_initimage_size
);
994 __pthread_init_static_tls (struct link_map
*map
)
996 lll_lock (stack_cache_lock
);
998 /* Iterate over the list with system-allocated threads first. */
1000 list_for_each (runp
, &stack_used
)
1001 init_one_static_tls (list_entry (runp
, struct pthread
, list
), map
);
1003 /* Now the list with threads using user-allocated stacks. */
1004 list_for_each (runp
, &__stack_user
)
1005 init_one_static_tls (list_entry (runp
, struct pthread
, list
), map
);
1007 lll_unlock (stack_cache_lock
);
1013 __wait_lookup_done (void)
1015 lll_lock (stack_cache_lock
);
1017 struct pthread
*self
= THREAD_SELF
;
1019 /* Iterate over the list with system-allocated threads first. */
1021 list_for_each (runp
, &stack_used
)
1023 struct pthread
*t
= list_entry (runp
, struct pthread
, list
);
1024 if (t
== self
|| t
->header
.gscope_flag
== THREAD_GSCOPE_FLAG_UNUSED
)
1027 int *const gscope_flagp
= &t
->header
.gscope_flag
;
1029 /* We have to wait until this thread is done with the global
1030 scope. First tell the thread that we are waiting and
1031 possibly have to be woken. */
1032 if (atomic_compare_and_exchange_bool_acq (gscope_flagp
,
1033 THREAD_GSCOPE_FLAG_WAIT
,
1034 THREAD_GSCOPE_FLAG_USED
))
1038 lll_private_futex_wait (gscope_flagp
, THREAD_GSCOPE_FLAG_WAIT
);
1039 while (*gscope_flagp
== THREAD_GSCOPE_FLAG_WAIT
);
1042 /* Now the list with threads using user-allocated stacks. */
1043 list_for_each (runp
, &__stack_user
)
1045 struct pthread
*t
= list_entry (runp
, struct pthread
, list
);
1046 if (t
== self
|| t
->header
.gscope_flag
== THREAD_GSCOPE_FLAG_UNUSED
)
1049 int *const gscope_flagp
= &t
->header
.gscope_flag
;
1051 /* We have to wait until this thread is done with the global
1052 scope. First tell the thread that we are waiting and
1053 possibly have to be woken. */
1054 if (atomic_compare_and_exchange_bool_acq (gscope_flagp
,
1055 THREAD_GSCOPE_FLAG_WAIT
,
1056 THREAD_GSCOPE_FLAG_USED
))
1060 lll_private_futex_wait (gscope_flagp
, THREAD_GSCOPE_FLAG_WAIT
);
1061 while (*gscope_flagp
== THREAD_GSCOPE_FLAG_WAIT
);
1064 lll_unlock (stack_cache_lock
);