From: Rich Felker Date: Fri, 26 Apr 2013 21:51:22 +0000 (-0400) Subject: prevent code from running under a thread id which already gave ESRCH X-Git-Tag: v0.9.11~64 X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=d674f8582ae8897715782ab9dfb5a039a9112a86;p=oweals%2Fmusl.git prevent code from running under a thread id which already gave ESRCH --- diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c index cf9cb191..6e49acdc 100644 --- a/src/thread/pthread_create.c +++ b/src/thread/pthread_create.c @@ -30,7 +30,6 @@ _Noreturn void pthread_exit(void *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 @@ -38,6 +37,13 @@ _Noreturn void pthread_exit(void *result) * reasons as well. */ __syscall(SYS_rt_sigprocmask, SIG_BLOCK, SIGALL_SET, &set, _NSIG/8); + /* 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); + /* 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