#include <linux/slab.h>
#include <linux/seq_file.h>
#include <linux/err.h>
+#include <keys/user-type.h>
#include <asm/uaccess.h>
#include "internal.h"
-static int user_instantiate(struct key *key, const void *data, size_t datalen);
-static int user_duplicate(struct key *key, const struct key *source);
-static int user_update(struct key *key, const void *data, size_t datalen);
-static int user_match(const struct key *key, const void *criterion);
-static void user_destroy(struct key *key);
-static void user_describe(const struct key *user, struct seq_file *m);
-static long user_read(const struct key *key,
- char __user *buffer, size_t buflen);
-
/*
* user defined keys take an arbitrary string as the description and an
* arbitrary blob of data as the payload
struct key_type key_type_user = {
.name = "user",
.instantiate = user_instantiate,
- .duplicate = user_duplicate,
.update = user_update,
.match = user_match,
.destroy = user_destroy,
.read = user_read,
};
+EXPORT_SYMBOL_GPL(key_type_user);
+
/*****************************************************************************/
/*
* instantiate a user defined key
*/
-static int user_instantiate(struct key *key, const void *data, size_t datalen)
+int user_instantiate(struct key *key, const void *data, size_t datalen)
{
+ struct user_key_payload *upayload;
int ret;
ret = -EINVAL;
if (ret < 0)
goto error;
- /* attach the data */
ret = -ENOMEM;
- key->payload.data = kmalloc(datalen, GFP_KERNEL);
- if (!key->payload.data)
+ upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL);
+ if (!upayload)
goto error;
- memcpy(key->payload.data, data, datalen);
+ /* attach the data */
+ upayload->datalen = datalen;
+ memcpy(upayload->data, data, datalen);
+ rcu_assign_pointer(key->payload.data, upayload);
ret = 0;
- error:
+error:
return ret;
} /* end user_instantiate() */
+EXPORT_SYMBOL_GPL(user_instantiate);
/*****************************************************************************/
/*
- * duplicate a user defined key
+ * dispose of the old data from an updated user defined key
*/
-static int user_duplicate(struct key *key, const struct key *source)
+static void user_update_rcu_disposal(struct rcu_head *rcu)
{
- int ret;
-
- /* just copy the payload */
- ret = -ENOMEM;
- key->payload.data = kmalloc(source->datalen, GFP_KERNEL);
+ struct user_key_payload *upayload;
- if (key->payload.data) {
- key->datalen = source->datalen;
- memcpy(key->payload.data, source->payload.data, source->datalen);
- ret = 0;
- }
+ upayload = container_of(rcu, struct user_key_payload, rcu);
- return ret;
+ kfree(upayload);
-} /* end user_duplicate() */
+} /* end user_update_rcu_disposal() */
/*****************************************************************************/
/*
* update a user defined key
+ * - the key's semaphore is write-locked
*/
-static int user_update(struct key *key, const void *data, size_t datalen)
+int user_update(struct key *key, const void *data, size_t datalen)
{
- void *new, *zap;
+ struct user_key_payload *upayload, *zap;
int ret;
ret = -EINVAL;
if (datalen <= 0 || datalen > 32767 || !data)
goto error;
- /* copy the data */
+ /* construct a replacement payload */
ret = -ENOMEM;
- new = kmalloc(datalen, GFP_KERNEL);
- if (!new)
+ upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL);
+ if (!upayload)
goto error;
- memcpy(new, data, datalen);
+ upayload->datalen = datalen;
+ memcpy(upayload->data, data, datalen);
/* check the quota and attach the new data */
- zap = new;
- write_lock(&key->lock);
+ zap = upayload;
ret = key_payload_reserve(key, datalen);
if (ret == 0) {
/* attach the new data, displacing the old */
zap = key->payload.data;
- key->payload.data = new;
+ rcu_assign_pointer(key->payload.data, upayload);
key->expiry = 0;
}
- write_unlock(&key->lock);
- kfree(zap);
+ call_rcu(&zap->rcu, user_update_rcu_disposal);
- error:
+error:
return ret;
} /* end user_update() */
+EXPORT_SYMBOL_GPL(user_update);
+
/*****************************************************************************/
/*
* match users on their name
*/
-static int user_match(const struct key *key, const void *description)
+int user_match(const struct key *key, const void *description)
{
return strcmp(key->description, description) == 0;
} /* end user_match() */
+EXPORT_SYMBOL_GPL(user_match);
+
/*****************************************************************************/
/*
* dispose of the data dangling from the corpse of a user
*/
-static void user_destroy(struct key *key)
+void user_destroy(struct key *key)
{
- kfree(key->payload.data);
+ struct user_key_payload *upayload = key->payload.data;
+
+ kfree(upayload);
} /* end user_destroy() */
+EXPORT_SYMBOL_GPL(user_destroy);
+
/*****************************************************************************/
/*
- * describe the user
+ * describe the user key
*/
-static void user_describe(const struct key *key, struct seq_file *m)
+void user_describe(const struct key *key, struct seq_file *m)
{
seq_puts(m, key->description);
} /* end user_describe() */
+EXPORT_SYMBOL_GPL(user_describe);
+
/*****************************************************************************/
/*
* read the key data
+ * - the key's semaphore is read-locked
*/
-static long user_read(const struct key *key,
- char __user *buffer, size_t buflen)
+long user_read(const struct key *key, char __user *buffer, size_t buflen)
{
- long ret = key->datalen;
+ struct user_key_payload *upayload;
+ long ret;
+
+ upayload = rcu_dereference(key->payload.data);
+ ret = upayload->datalen;
/* we can return the data as is */
if (buffer && buflen > 0) {
- if (buflen > key->datalen)
- buflen = key->datalen;
+ if (buflen > upayload->datalen)
+ buflen = upayload->datalen;
- if (copy_to_user(buffer, key->payload.data, buflen) != 0)
+ if (copy_to_user(buffer, upayload->data, buflen) != 0)
ret = -EFAULT;
}
return ret;
} /* end user_read() */
+
+EXPORT_SYMBOL_GPL(user_read);
git://git.onelab.eu / linux-2.6.git / blobdiff