fix race condition in pthread_kill

[musl] / src / thread / pthread_kill.c

diff --git a/src/thread/pthread_kill.c b/src/thread/pthread_kill.c
index 9d85fa5..a24ecc2 100644 (file)
--- a/src/thread/pthread_kill.c
+++ b/src/thread/pthread_kill.c
@@ -1,7 +1,10 @@
-#define SYSCALL_RETURN_ERRNO
 #include "pthread_impl.h"
 
 int pthread_kill(pthread_t t, int sig)
 {
-       return syscall3(__NR_tgkill, t->pid, t->tid, sig);
+       int r;
+       __lock(&t->killlock);
+       r = t->dead ? ESRCH : -__syscall(SYS_tgkill, t->pid, t->tid, sig);
+       a_store(&t->killlock, 0);
+       return r;
 }