osigblock
(void)__sys_sigprocmask(SIG_SETMASK, &osigblock, NULL);
if (!sigismember(&osigblock, SIGCHLD))
sigset_t sigblock, osigblock;
(void)__libc_sigprocmask(SIG_BLOCK, &sigblock, &osigblock);
int osigblock(struct thread *, struct osigblock_args *);