run_stack
retval = run_stack(pamh, flags, PAM_AUTH_MODULE, PAM_AUTH_ERR,
retval = run_stack(pamh, flags, PAM_AUTH_MODULE, PAM_CRED_ERR,
retval = run_stack(pamh, flags, PAM_ACCOUNT_MODULE, PAM_ACCT_EXPIRED,
retval = run_stack(pamh, flags, PAM_SESSION_MODULE, PAM_SESSION_ERR,
retval = run_stack(pamh, flags, PAM_SESSION_MODULE, PAM_SESSION_ERR,
retval = run_stack(pamh, flags | PAM_PRELIM_CHECK, PAM_PASSWORD_MODULE,
retval = run_stack(pamh, flags | PAM_UPDATE_AUTHTOK,