_Noreturn void pthread_exit(void *result)
{
pthread_t self = pthread_self();
+ sigset_t set;
self->result = result;
/* Mark this thread dead before decrementing count */
__lock(self->killlock);
self->dead = 1;
- __unlock(self->killlock);
/* Block all signals before decrementing the live thread count.
* This is important to ensure that dynamically allocated TLS
* is not under-allocated/over-committed, and possibly for other
* reasons as well. */
- __syscall(SYS_rt_sigprocmask, SIG_BLOCK, SIGALL_SET, 0, _NSIG/8);
+ __block_all_sigs(&set);
+
+ /* Wait to unlock the kill lock, which governs functions like
+ * pthread_kill which target a thread id, until signals have
+ * been blocked. This precludes observation of the thread id
+ * as a live thread (with application code running in it) after
+ * the thread was reported dead by ESRCH being returned. */
+ __unlock(self->killlock);
- if (a_fetch_add(&libc.threads_minus_1, -1)==0) exit(0);
+ /* It's impossible to determine whether this is "the last thread"
+ * until performing the atomic decrement, since multiple threads
+ * could exit at the same time. For the last thread, revert the
+ * decrement and unblock signals to give the atexit handlers and
+ * stdio cleanup code a consistent state. */
+ if (a_fetch_add(&libc.threads_minus_1, -1)==0) {
+ libc.threads_minus_1 = 0;
+ __restore_sigs(&set);
+ exit(0);
+ }
if (self->detached && self->map_base) {
/* Detached threads must avoid the kernel clear_child_tid
self->detached = 2;
pthread_exit(0);
}
- __syscall(SYS_rt_sigprocmask, SIG_SETMASK,
- self->sigmask, 0, _NSIG/8);
+ __restore_sigs(self->sigmask);
}
if (self->unblock_cancel)
__syscall(SYS_rt_sigprocmask, SIG_UNBLOCK,
}
if (attr._a_sched) {
do_sched = new->startlock[0] = 1;
- __syscall(SYS_rt_sigprocmask, SIG_BLOCK,
- SIGALL_SET, self->sigmask, _NSIG/8);
+ __block_app_sigs(new->sigmask);
}
new->unblock_cancel = self->cancel;
new->canary = self->canary;
__release_ptc();
if (do_sched) {
- __syscall(SYS_rt_sigprocmask, SIG_SETMASK,
- new->sigmask, 0, _NSIG/8);
+ __restore_sigs(new->sigmask);
}
if (ret < 0) {