_rtld_tls_allocate
tcb = _rtld_tls_allocate();
__weak_alias(_rtld_tls_allocate, __libc_rtld_tls_allocate)
_rtld_tls_allocate(void)
private_area = newthread->pt_tls = _rtld_tls_allocate();
struct tls_tcb *_rtld_tls_allocate(void);