Rich Felker | f68a346 | 2013-09-16 10:54:31 -0400 | [diff] [blame] | 1 | #define _GNU_SOURCE |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 2 | #include "pthread_impl.h" |
Rich Felker | dba68bf | 2011-07-30 08:02:14 -0400 | [diff] [blame] | 3 | #include "stdio_impl.h" |
Szabolcs Nagy | b20760c | 2013-09-15 02:00:32 +0000 | [diff] [blame] | 4 | #include "libc.h" |
Rich Felker | efd4d87 | 2012-11-08 17:04:20 -0500 | [diff] [blame] | 5 | #include <sys/mman.h> |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 6 | |
Rich Felker | b2486a8 | 2011-04-06 20:27:07 -0400 | [diff] [blame] | 7 | static void dummy_0() |
| 8 | { |
| 9 | } |
Rich Felker | dcd6037 | 2012-10-05 11:51:50 -0400 | [diff] [blame] | 10 | weak_alias(dummy_0, __acquire_ptc); |
| 11 | weak_alias(dummy_0, __release_ptc); |
Rich Felker | a6054e3 | 2011-04-19 23:09:14 -0400 | [diff] [blame] | 12 | weak_alias(dummy_0, __pthread_tsd_run_dtors); |
Rich Felker | fd80cfa | 2011-04-03 02:33:50 -0400 | [diff] [blame] | 13 | |
Rich Felker | 0c05bd3 | 2012-09-06 23:34:10 -0400 | [diff] [blame] | 14 | _Noreturn void pthread_exit(void *result) |
Rich Felker | 1a9a2ff | 2011-02-13 19:58:30 -0500 | [diff] [blame] | 15 | { |
Rich Felker | 1ebde9c | 2011-04-17 17:06:05 -0400 | [diff] [blame] | 16 | pthread_t self = pthread_self(); |
Rich Felker | d0ba098 | 2013-04-26 16:16:04 -0400 | [diff] [blame] | 17 | sigset_t set; |
Rich Felker | 1a9a2ff | 2011-02-13 19:58:30 -0500 | [diff] [blame] | 18 | |
Rich Felker | afc35d5 | 2012-02-09 02:33:08 -0500 | [diff] [blame] | 19 | self->result = result; |
| 20 | |
| 21 | while (self->cancelbuf) { |
| 22 | void (*f)(void *) = self->cancelbuf->__f; |
| 23 | void *x = self->cancelbuf->__x; |
| 24 | self->cancelbuf = self->cancelbuf->__next; |
| 25 | f(x); |
Rich Felker | 1ebde9c | 2011-04-17 17:06:05 -0400 | [diff] [blame] | 26 | } |
Rich Felker | 1a9a2ff | 2011-02-13 19:58:30 -0500 | [diff] [blame] | 27 | |
Rich Felker | a6054e3 | 2011-04-19 23:09:14 -0400 | [diff] [blame] | 28 | __pthread_tsd_run_dtors(); |
Rich Felker | 1a9a2ff | 2011-02-13 19:58:30 -0500 | [diff] [blame] | 29 | |
Rich Felker | bbbe87e | 2012-07-12 11:23:43 -0400 | [diff] [blame] | 30 | __lock(self->exitlock); |
Rich Felker | f58c8a0 | 2011-06-14 01:25:17 -0400 | [diff] [blame] | 31 | |
Rich Felker | 5fcebcd | 2011-03-10 18:31:37 -0500 | [diff] [blame] | 32 | /* Mark this thread dead before decrementing count */ |
Rich Felker | bbbe87e | 2012-07-12 11:23:43 -0400 | [diff] [blame] | 33 | __lock(self->killlock); |
Rich Felker | 5fcebcd | 2011-03-10 18:31:37 -0500 | [diff] [blame] | 34 | self->dead = 1; |
Rich Felker | 19eb13b | 2011-02-19 11:04:36 -0500 | [diff] [blame] | 35 | |
Rich Felker | 6e531f9 | 2013-04-26 16:04:30 -0400 | [diff] [blame] | 36 | /* Block all signals before decrementing the live thread count. |
| 37 | * This is important to ensure that dynamically allocated TLS |
| 38 | * is not under-allocated/over-committed, and possibly for other |
| 39 | * reasons as well. */ |
Rich Felker | 2c074b0 | 2013-04-26 19:48:01 -0400 | [diff] [blame] | 40 | __block_all_sigs(&set); |
Rich Felker | 23f21c3 | 2013-04-26 15:47:44 -0400 | [diff] [blame] | 41 | |
Rich Felker | d674f85 | 2013-04-26 17:51:22 -0400 | [diff] [blame] | 42 | /* Wait to unlock the kill lock, which governs functions like |
| 43 | * pthread_kill which target a thread id, until signals have |
| 44 | * been blocked. This precludes observation of the thread id |
| 45 | * as a live thread (with application code running in it) after |
| 46 | * the thread was reported dead by ESRCH being returned. */ |
| 47 | __unlock(self->killlock); |
| 48 | |
Rich Felker | d0ba098 | 2013-04-26 16:16:04 -0400 | [diff] [blame] | 49 | /* It's impossible to determine whether this is "the last thread" |
| 50 | * until performing the atomic decrement, since multiple threads |
| 51 | * could exit at the same time. For the last thread, revert the |
| 52 | * decrement and unblock signals to give the atexit handlers and |
| 53 | * stdio cleanup code a consistent state. */ |
| 54 | if (a_fetch_add(&libc.threads_minus_1, -1)==0) { |
| 55 | libc.threads_minus_1 = 0; |
Rich Felker | 2c074b0 | 2013-04-26 19:48:01 -0400 | [diff] [blame] | 56 | __restore_sigs(&set); |
Rich Felker | d0ba098 | 2013-04-26 16:16:04 -0400 | [diff] [blame] | 57 | exit(0); |
| 58 | } |
Rich Felker | fb11b6b | 2011-02-19 10:38:57 -0500 | [diff] [blame] | 59 | |
Rich Felker | 5fcebcd | 2011-03-10 18:31:37 -0500 | [diff] [blame] | 60 | if (self->detached && self->map_base) { |
Rich Felker | 6e531f9 | 2013-04-26 16:04:30 -0400 | [diff] [blame] | 61 | /* Detached threads must avoid the kernel clear_child_tid |
| 62 | * feature, since the virtual address will have been |
| 63 | * unmapped and possibly already reused by a new mapping |
| 64 | * at the time the kernel would perform the write. In |
| 65 | * the case of threads that started out detached, the |
| 66 | * initial clone flags are correct, but if the thread was |
| 67 | * detached later (== 2), we need to clear it here. */ |
| 68 | if (self->detached == 2) __syscall(SYS_set_tid_address, 0); |
| 69 | |
| 70 | /* The following call unmaps the thread's stack mapping |
| 71 | * and then exits without touching the stack. */ |
Rich Felker | 1a9a2ff | 2011-02-13 19:58:30 -0500 | [diff] [blame] | 72 | __unmapself(self->map_base, self->map_size); |
Rich Felker | 5fcebcd | 2011-03-10 18:31:37 -0500 | [diff] [blame] | 73 | } |
Rich Felker | 1a9a2ff | 2011-02-13 19:58:30 -0500 | [diff] [blame] | 74 | |
Rich Felker | 0c05bd3 | 2012-09-06 23:34:10 -0400 | [diff] [blame] | 75 | for (;;) __syscall(SYS_exit, 0); |
Rich Felker | 1a9a2ff | 2011-02-13 19:58:30 -0500 | [diff] [blame] | 76 | } |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 77 | |
Rich Felker | cfd892f | 2012-05-23 14:13:54 -0400 | [diff] [blame] | 78 | void __do_cleanup_push(struct __ptcb *cb) |
Rich Felker | 5f37fc1 | 2011-08-03 19:57:46 -0400 | [diff] [blame] | 79 | { |
| 80 | struct pthread *self = pthread_self(); |
| 81 | cb->__next = self->cancelbuf; |
| 82 | self->cancelbuf = cb; |
| 83 | } |
| 84 | |
Rich Felker | cfd892f | 2012-05-23 14:13:54 -0400 | [diff] [blame] | 85 | void __do_cleanup_pop(struct __ptcb *cb) |
Rich Felker | 5f37fc1 | 2011-08-03 19:57:46 -0400 | [diff] [blame] | 86 | { |
Rich Felker | afc35d5 | 2012-02-09 02:33:08 -0500 | [diff] [blame] | 87 | __pthread_self()->cancelbuf = cb->__next; |
Rich Felker | 5f37fc1 | 2011-08-03 19:57:46 -0400 | [diff] [blame] | 88 | } |
| 89 | |
Rich Felker | 3f72cda | 2011-09-18 10:14:37 -0400 | [diff] [blame] | 90 | static int start(void *p) |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 91 | { |
Rich Felker | 3f72cda | 2011-09-18 10:14:37 -0400 | [diff] [blame] | 92 | pthread_t self = p; |
Rich Felker | 1e21e78 | 2012-11-11 15:38:04 -0500 | [diff] [blame] | 93 | if (self->startlock[0]) { |
| 94 | __wait(self->startlock, 0, 1, 1); |
| 95 | if (self->startlock[0]) { |
| 96 | self->detached = 2; |
| 97 | pthread_exit(0); |
| 98 | } |
Rich Felker | 2c074b0 | 2013-04-26 19:48:01 -0400 | [diff] [blame] | 99 | __restore_sigs(self->sigmask); |
Rich Felker | 1e21e78 | 2012-11-11 15:38:04 -0500 | [diff] [blame] | 100 | } |
Rich Felker | 99b8a25 | 2011-05-07 23:23:58 -0400 | [diff] [blame] | 101 | if (self->unblock_cancel) |
Rich Felker | 2f43704 | 2012-08-09 22:52:13 -0400 | [diff] [blame] | 102 | __syscall(SYS_rt_sigprocmask, SIG_UNBLOCK, |
Rich Felker | ccc7b4c | 2013-03-26 23:07:31 -0400 | [diff] [blame] | 103 | SIGPT_SET, 0, _NSIG/8); |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 104 | pthread_exit(self->start(self->start_arg)); |
Rich Felker | 3f72cda | 2011-09-18 10:14:37 -0400 | [diff] [blame] | 105 | return 0; |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 106 | } |
| 107 | |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 108 | #define ROUND(x) (((x)+PAGE_SIZE-1)&-PAGE_SIZE) |
| 109 | |
| 110 | /* pthread_key_create.c overrides this */ |
| 111 | static const size_t dummy = 0; |
| 112 | weak_alias(dummy, __pthread_tsd_size); |
| 113 | |
Rich Felker | dba68bf | 2011-07-30 08:02:14 -0400 | [diff] [blame] | 114 | static FILE *const dummy_file = 0; |
| 115 | weak_alias(dummy_file, __stdin_used); |
| 116 | weak_alias(dummy_file, __stdout_used); |
| 117 | weak_alias(dummy_file, __stderr_used); |
| 118 | |
| 119 | static void init_file_lock(FILE *f) |
| 120 | { |
| 121 | if (f && f->lock<0) f->lock = 0; |
| 122 | } |
| 123 | |
Rich Felker | dcd6037 | 2012-10-05 11:51:50 -0400 | [diff] [blame] | 124 | void *__copy_tls(unsigned char *); |
Rich Felker | 8431d79 | 2012-10-04 16:35:46 -0400 | [diff] [blame] | 125 | |
Rich Felker | d514264 | 2013-02-01 22:10:40 -0500 | [diff] [blame] | 126 | int pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict attrp, void *(*entry)(void *), void *restrict arg) |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 127 | { |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 128 | int ret; |
Rich Felker | d514264 | 2013-02-01 22:10:40 -0500 | [diff] [blame] | 129 | size_t size, guard; |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 130 | struct pthread *self = pthread_self(), *new; |
Rich Felker | 14a835b | 2013-03-31 23:25:55 -0400 | [diff] [blame] | 131 | unsigned char *map = 0, *stack = 0, *tsd = 0, *stack_limit; |
Rich Felker | f68a346 | 2013-09-16 10:54:31 -0400 | [diff] [blame] | 132 | unsigned flags = CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND |
Rich Felker | 271c211 | 2013-09-16 10:56:01 -0400 | [diff] [blame^] | 133 | | CLONE_THREAD | CLONE_SYSVSEM | CLONE_SETTLS |
Rich Felker | f68a346 | 2013-09-16 10:54:31 -0400 | [diff] [blame] | 134 | | CLONE_PARENT_SETTID | CLONE_CHILD_CLEARTID | CLONE_DETACHED; |
Rich Felker | 1e21e78 | 2012-11-11 15:38:04 -0500 | [diff] [blame] | 135 | int do_sched = 0; |
Rich Felker | d514264 | 2013-02-01 22:10:40 -0500 | [diff] [blame] | 136 | pthread_attr_t attr = {0}; |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 137 | |
Rich Felker | 7fd3995 | 2011-04-03 16:15:15 -0400 | [diff] [blame] | 138 | if (!self) return ENOSYS; |
Rich Felker | 9080cc1 | 2011-04-17 16:53:54 -0400 | [diff] [blame] | 139 | if (!libc.threaded) { |
Rich Felker | dba68bf | 2011-07-30 08:02:14 -0400 | [diff] [blame] | 140 | for (FILE *f=libc.ofl_head; f; f=f->next) |
| 141 | init_file_lock(f); |
| 142 | init_file_lock(__stdin_used); |
| 143 | init_file_lock(__stdout_used); |
| 144 | init_file_lock(__stderr_used); |
Rich Felker | 9080cc1 | 2011-04-17 16:53:54 -0400 | [diff] [blame] | 145 | libc.threaded = 1; |
| 146 | } |
Rich Felker | d514264 | 2013-02-01 22:10:40 -0500 | [diff] [blame] | 147 | if (attrp) attr = *attrp; |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 148 | |
Rich Felker | dcd6037 | 2012-10-05 11:51:50 -0400 | [diff] [blame] | 149 | __acquire_ptc(); |
| 150 | |
Rich Felker | d514264 | 2013-02-01 22:10:40 -0500 | [diff] [blame] | 151 | if (attr._a_stackaddr) { |
| 152 | size_t need = libc.tls_size + __pthread_tsd_size; |
| 153 | size = attr._a_stacksize + DEFAULT_STACK_SIZE; |
| 154 | stack = (void *)(attr._a_stackaddr & -16); |
Rich Felker | ced6499 | 2013-04-06 01:15:08 -0400 | [diff] [blame] | 155 | stack_limit = (void *)(attr._a_stackaddr - size); |
Rich Felker | d514264 | 2013-02-01 22:10:40 -0500 | [diff] [blame] | 156 | /* Use application-provided stack for TLS only when |
| 157 | * it does not take more than ~12% or 2k of the |
| 158 | * application's stack space. */ |
| 159 | if (need < size/8 && need < 2048) { |
| 160 | tsd = stack - __pthread_tsd_size; |
| 161 | stack = tsd - libc.tls_size; |
| 162 | } else { |
| 163 | size = ROUND(need); |
| 164 | guard = 0; |
Rich Felker | 819006a | 2012-06-09 19:53:29 -0400 | [diff] [blame] | 165 | } |
Rich Felker | d514264 | 2013-02-01 22:10:40 -0500 | [diff] [blame] | 166 | } else { |
| 167 | guard = ROUND(DEFAULT_GUARD_SIZE + attr._a_guardsize); |
| 168 | size = guard + ROUND(DEFAULT_STACK_SIZE + attr._a_stacksize |
| 169 | + libc.tls_size + __pthread_tsd_size); |
| 170 | } |
| 171 | |
| 172 | if (!tsd) { |
Rich Felker | 8431d79 | 2012-10-04 16:35:46 -0400 | [diff] [blame] | 173 | if (guard) { |
| 174 | map = mmap(0, size, PROT_NONE, MAP_PRIVATE|MAP_ANON, -1, 0); |
Rich Felker | 72768ea | 2013-02-01 22:25:19 -0500 | [diff] [blame] | 175 | if (map == MAP_FAILED) goto fail; |
Rich Felker | 8431d79 | 2012-10-04 16:35:46 -0400 | [diff] [blame] | 176 | if (mprotect(map+guard, size-guard, PROT_READ|PROT_WRITE)) { |
| 177 | munmap(map, size); |
Rich Felker | 72768ea | 2013-02-01 22:25:19 -0500 | [diff] [blame] | 178 | goto fail; |
Rich Felker | 8431d79 | 2012-10-04 16:35:46 -0400 | [diff] [blame] | 179 | } |
| 180 | } else { |
| 181 | map = mmap(0, size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON, -1, 0); |
Rich Felker | 72768ea | 2013-02-01 22:25:19 -0500 | [diff] [blame] | 182 | if (map == MAP_FAILED) goto fail; |
Rich Felker | 8431d79 | 2012-10-04 16:35:46 -0400 | [diff] [blame] | 183 | } |
Rich Felker | 819006a | 2012-06-09 19:53:29 -0400 | [diff] [blame] | 184 | tsd = map + size - __pthread_tsd_size; |
Rich Felker | 14a835b | 2013-03-31 23:25:55 -0400 | [diff] [blame] | 185 | if (!stack) { |
| 186 | stack = tsd - libc.tls_size; |
| 187 | stack_limit = map + guard; |
| 188 | } |
Rich Felker | 11e4b92 | 2011-05-07 23:39:48 -0400 | [diff] [blame] | 189 | } |
Rich Felker | d514264 | 2013-02-01 22:10:40 -0500 | [diff] [blame] | 190 | |
| 191 | new = __copy_tls(tsd - libc.tls_size); |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 192 | new->map_base = map; |
| 193 | new->map_size = size; |
Rich Felker | 14a835b | 2013-03-31 23:25:55 -0400 | [diff] [blame] | 194 | new->stack = stack; |
| 195 | new->stack_size = stack - stack_limit; |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 196 | new->pid = self->pid; |
| 197 | new->errno_ptr = &new->errno_val; |
| 198 | new->start = entry; |
| 199 | new->start_arg = arg; |
| 200 | new->self = new; |
| 201 | new->tsd = (void *)tsd; |
Rich Felker | d514264 | 2013-02-01 22:10:40 -0500 | [diff] [blame] | 202 | if (attr._a_detach) { |
Rich Felker | 92f8396 | 2012-07-11 23:36:46 -0400 | [diff] [blame] | 203 | new->detached = 1; |
Rich Felker | f68a346 | 2013-09-16 10:54:31 -0400 | [diff] [blame] | 204 | flags -= CLONE_CHILD_CLEARTID; |
Rich Felker | 92f8396 | 2012-07-11 23:36:46 -0400 | [diff] [blame] | 205 | } |
Rich Felker | d514264 | 2013-02-01 22:10:40 -0500 | [diff] [blame] | 206 | if (attr._a_sched) { |
Rich Felker | 1e21e78 | 2012-11-11 15:38:04 -0500 | [diff] [blame] | 207 | do_sched = new->startlock[0] = 1; |
Rich Felker | 2c074b0 | 2013-04-26 19:48:01 -0400 | [diff] [blame] | 208 | __block_app_sigs(new->sigmask); |
Rich Felker | 1e21e78 | 2012-11-11 15:38:04 -0500 | [diff] [blame] | 209 | } |
Rich Felker | bf619d8 | 2011-03-29 12:58:22 -0400 | [diff] [blame] | 210 | new->unblock_cancel = self->cancel; |
Rich Felker | 0a96a37 | 2012-10-07 21:43:46 -0400 | [diff] [blame] | 211 | new->canary = self->canary; |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 212 | |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 213 | a_inc(&libc.threads_minus_1); |
Rich Felker | 9ec4283 | 2012-10-15 18:51:53 -0400 | [diff] [blame] | 214 | ret = __clone(start, stack, flags, new, &new->tid, TP_ADJ(new), &new->tid); |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 215 | |
Rich Felker | dcd6037 | 2012-10-05 11:51:50 -0400 | [diff] [blame] | 216 | __release_ptc(); |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 217 | |
Rich Felker | 1e21e78 | 2012-11-11 15:38:04 -0500 | [diff] [blame] | 218 | if (do_sched) { |
Rich Felker | 2c074b0 | 2013-04-26 19:48:01 -0400 | [diff] [blame] | 219 | __restore_sigs(new->sigmask); |
Rich Felker | 1e21e78 | 2012-11-11 15:38:04 -0500 | [diff] [blame] | 220 | } |
| 221 | |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 222 | if (ret < 0) { |
| 223 | a_dec(&libc.threads_minus_1); |
Rich Felker | 077549e | 2013-02-01 22:23:24 -0500 | [diff] [blame] | 224 | if (map) munmap(map, size); |
Rich Felker | 5966680 | 2011-02-15 02:20:21 -0500 | [diff] [blame] | 225 | return EAGAIN; |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 226 | } |
Rich Felker | 1e21e78 | 2012-11-11 15:38:04 -0500 | [diff] [blame] | 227 | |
| 228 | if (do_sched) { |
| 229 | ret = __syscall(SYS_sched_setscheduler, new->tid, |
Rich Felker | d514264 | 2013-02-01 22:10:40 -0500 | [diff] [blame] | 230 | attr._a_policy, &attr._a_prio); |
Rich Felker | 1e21e78 | 2012-11-11 15:38:04 -0500 | [diff] [blame] | 231 | a_store(new->startlock, ret<0 ? 2 : 0); |
| 232 | __wake(new->startlock, 1, 1); |
| 233 | if (ret < 0) return -ret; |
| 234 | } |
| 235 | |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 236 | *res = new; |
| 237 | return 0; |
Rich Felker | 72768ea | 2013-02-01 22:25:19 -0500 | [diff] [blame] | 238 | fail: |
| 239 | __release_ptc(); |
| 240 | return EAGAIN; |
Rich Felker | 0b44a03 | 2011-02-12 00:22:29 -0500 | [diff] [blame] | 241 | } |