I added, then removed and now I add this again :). Hopefully I got it rigth this time.

libpthread/linuxthreads/pthread.c

@@ -376,6 +376,7 @@ static void pthread_initialize(void)
   sa.sa_flags = 0;
   __libc_sigaction(__pthread_sig_restart, &sa, NULL);
   sa.sa_handler = pthread_handle_sigcancel;
+  sigaddset(&sa.sa_mask, __pthread_sig_restart);
   // sa.sa_flags = 0;
   __libc_sigaction(__pthread_sig_cancel, &sa, NULL);
   if (__pthread_sig_debug > 0) {