security: keys: Replace time_t with time64_t for struct key_preparsed_payload

The 'struct key_preparsed_payload' will use 'time_t' which we will
try to remove in the kernel, since 'time_t' is not year 2038 safe on
32bits systems.

Thus this patch replaces 'time_t' with 'time64_t' which is year 2038
safe on 32 bits system for 'struct key_preparsed_payload', moreover
we should use the 'TIME64_MAX' macro to initialize the 'time64_t'
type variable.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>

include/linux/key-type.h

@@ -44,7 +44,7 @@ struct key_preparsed_payload {
 	const void	*data;		/* Raw data */
 	size_t		datalen;	/* Raw datalen */
 	size_t		quotalen;	/* Quota length for proposed payload */
-	time_t		expiry;		/* Expiry time of key */
+	time64_t	expiry;		/* Expiry time of key */
 } __randomize_layout;
 
 typedef int (*request_key_actor_t)(struct key_construction *key,

security/keys/key.c

@@ -460,7 +460,7 @@ static int __key_instantiate_and_link(struct key *key,
 			if (authkey)
 				key_revoke(authkey);
 
-			if (prep->expiry != TIME_T_MAX) {
+			if (prep->expiry != TIME64_MAX) {
 				key->expiry = prep->expiry;
 				key_schedule_gc(prep->expiry + key_gc_delay);
 			}
@@ -506,7 +506,7 @@ int key_instantiate_and_link(struct key *key,
 	prep.data = data;
 	prep.datalen = datalen;
 	prep.quotalen = key->type->def_datalen;
-	prep.expiry = TIME_T_MAX;
+	prep.expiry = TIME64_MAX;
 	if (key->type->preparse) {
 		ret = key->type->preparse(&prep);
 		if (ret < 0)
@@ -845,7 +845,7 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
 	prep.data = payload;
 	prep.datalen = plen;
 	prep.quotalen = index_key.type->def_datalen;
-	prep.expiry = TIME_T_MAX;
+	prep.expiry = TIME64_MAX;
 	if (index_key.type->preparse) {
 		ret = index_key.type->preparse(&prep);
 		if (ret < 0) {
@@ -989,7 +989,7 @@ int key_update(key_ref_t key_ref, const void *payload, size_t plen)
 	prep.data = payload;
 	prep.datalen = plen;
 	prep.quotalen = key->type->def_datalen;
-	prep.expiry = TIME_T_MAX;
+	prep.expiry = TIME64_MAX;
 	if (key->type->preparse) {
 		ret = key->type->preparse(&prep);
 		if (ret < 0)