@@ -1151,8 +1151,21 @@ access the data:
usage. This is called key->payload.rcu_data0. The following accessors
wrap the RCU calls to this element:
- rcu_assign_keypointer(struct key *key, void *data);
- void *rcu_dereference_key(struct key *key);
+ (a) Set or change the first payload pointer:
+
+ rcu_assign_keypointer(struct key *key, void *data);
+
+ (b) Read the first payload pointer with the key semaphore held:
+
+ [const] void *dereference_key_locked([const] struct key *key);
+
+ Note that the return value will inherit its constness from the key
+ parameter. Static analysis will give an error if it things the lock
+ isn't held.
+
+ (c) Read the first payload pointer with the RCU read lock held:
+
+ const void *dereference_key_rcu(const struct key *key);
===================
@@ -329,7 +329,7 @@ static void fscache_objlist_config(struct fscache_objlist_data *data)
config = 0;
rcu_read_lock();
- confkey = user_key_payload(key);
+ confkey = user_key_payload_rcu(key);
buf = confkey->data;
for (len = confkey->datalen - 1; len >= 0; len--) {
@@ -316,7 +316,7 @@ static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
if (ret < 0)
goto out_up;
- payload = user_key_payload(rkey);
+ payload = user_key_payload_rcu(rkey);
if (IS_ERR_OR_NULL(payload)) {
ret = PTR_ERR(payload);
goto out_up;
@@ -48,9 +48,14 @@ extern void user_describe(const struct key *user, struct seq_file *m);
extern long user_read(const struct key *key,
char __user *buffer, size_t buflen);
-static inline const struct user_key_payload *user_key_payload(const struct key *key)
+static inline const struct user_key_payload *user_key_payload_rcu(const struct key *key)
{
- return (struct user_key_payload *)rcu_dereference_key(key);
+ return (struct user_key_payload *)dereference_key_rcu(key);
+}
+
+static inline struct user_key_payload *user_key_payload_locked(struct key *key)
+{
+ return (struct user_key_payload *)dereference_key_locked(key);
}
#endif /* CONFIG_KEYS */
@@ -354,7 +354,10 @@ static inline bool key_is_instantiated(const struct key *key)
!test_bit(KEY_FLAG_NEGATIVE, &key->flags);
}
-#define rcu_dereference_key(KEY) \
+#define dereference_key_rcu(KEY) \
+ (rcu_dereference((KEY)->payload.rcu_data0))
+
+#define dereference_key_locked(KEY) \
(rcu_dereference_protected((KEY)->payload.rcu_data0, \
rwsem_is_locked(&((struct key *)(KEY))->sem)))
@@ -70,7 +70,7 @@ int dns_query(const char *type, const char *name, size_t namelen,
const char *options, char **_result, time64_t *_expiry)
{
struct key *rkey;
- const struct user_key_payload *upayload;
+ struct user_key_payload *upayload;
const struct cred *saved_cred;
size_t typelen, desclen;
char *desc, *cp;
@@ -141,7 +141,7 @@ int dns_query(const char *type, const char *name, size_t namelen,
if (ret)
goto put;
- upayload = user_key_payload(rkey);
+ upayload = user_key_payload_locked(rkey);
len = upayload->datalen;
ret = -ENOMEM;
@@ -55,7 +55,7 @@ static ssize_t mpi_from_key(key_serial_t keyid, size_t maxlen, MPI *mpi)
if (status == 0) {
const struct user_key_payload *payload;
- payload = user_key_payload(key);
+ payload = user_key_payload_locked(key);
if (maxlen == 0) {
*mpi = NULL;
@@ -314,7 +314,7 @@ static struct key *request_user_key(const char *master_desc, const u8 **master_k
goto error;
down_read(&ukey->sem);
- upayload = user_key_payload(ukey);
+ upayload = user_key_payload_locked(ukey);
*master_key = upayload->data;
*master_keylen = upayload->datalen;
error:
@@ -926,7 +926,7 @@ static long encrypted_read(const struct key *key, char __user *buffer,
size_t asciiblob_len;
int ret;
- epayload = rcu_dereference_key(key);
+ epayload = dereference_key_locked(key);
/* returns the hex encoded iv, encrypted-data, and hmac as ascii */
asciiblob_len = epayload->datablob_len + ivsize + 1
@@ -1140,12 +1140,12 @@ static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
static long trusted_read(const struct key *key, char __user *buffer,
size_t buflen)
{
- struct trusted_key_payload *p;
+ const struct trusted_key_payload *p;
char *ascii_buf;
char *bufp;
int i;
- p = rcu_dereference_key(key);
+ p = dereference_key_locked(key);
if (!p)
return -EINVAL;
if (!buffer || buflen <= 0)
@@ -107,7 +107,7 @@ int user_update(struct key *key, struct key_preparsed_payload *prep)
/* attach the new data, displacing the old */
key->expiry = prep->expiry;
if (!test_bit(KEY_FLAG_NEGATIVE, &key->flags))
- zap = rcu_dereference_key(key);
+ zap = dereference_key_locked(key);
rcu_assign_keypointer(key, prep->payload.data[0]);
prep->payload.data[0] = NULL;
@@ -169,7 +169,7 @@ long user_read(const struct key *key, char __user *buffer, size_t buflen)
const struct user_key_payload *upayload;
long ret;
- upayload = user_key_payload(key);
+ upayload = user_key_payload_rcu(key);
ret = upayload->datalen;
/* we can return the data as is */