current_real_cred
if (filp->f_cred != current_real_cred()) {
put_cred(revert_creds(get_cred(current_real_cred())));
if (current_cred() != current_real_cred()) {
raw_smp_processor_id(), __kuid_val(current_real_cred()->euid),
__kuid_val(current_real_cred()->euid),
if (current_cred() != current_real_cred())