key_type_lookup

函数名称：Find and lock the specified key type against removal.* We return with the sem read-locked if successful. If the type wasn't* available -ENOKEY is returned instead.

函数原型：struct key_type *key_type_lookup(const char *type)

返回类型：struct key_type

参数：

类型	参数	名称
const char *	type

**调用者**
名称	描述
key_create_or_update	key_create_or_update - Update or create and instantiate a key.@keyring_ref: A pointer to the destination keyring with possession flag.@type: The type of key.*@description: The searchable description for the key.
keyring_restrict	keyring_restrict - Look up and apply a restriction to a keyring@keyring_ref: The keyring to be restricted@type: The key type that will provide the restriction checker.*@restriction: The restriction options to apply to the keyring
SYSCALL_DEFINE4	Search the process keyrings and keyring trees linked from those for a* matching key. Keyrings must have appropriate Search permission to be* searched.* If a key is found, it will be attached to the destination keyring if there's
keyctl_keyring_search	Search the specified keyring and any keyrings it links to for a matching* key

函数逻辑报告