KEYCTL_REVOKE
Marks a key as being revoked. After this operation has been performed on a key, attempts to access it will meet with error -EKEYREVOKED. Arguments
ecx | Key serial number. It may be one of the following special values:
`KEY_SPEC_THREAD_KEYRING` | `Caller's thread-specific keyring.`
`KEY_SPEC_PROCESS_KEYRING` | `Caller's process-specific keyring.`
`KEY_SPEC_SESSION_KEYRING` | `Caller's session-specific keyring.`
`KEY_SPEC_USER_KEYRING` | `Caller's UID-specific keyring.`
`KEY_SPEC_USER_SESSION_KEYRING` | `Caller's UID-session keyring.`
`KEY_SPEC_GROUP_KEYRING` | `Caller's GID-specific keyring.`
`KEY_SPEC_REQKEY_AUTH_KEY` | `This specifies the authorization key created by request_key() and passed to the process it spawns to generate a key. If a valid keyring ID is passed in, then this will simply be returned if the key exists; an error will be issued if it doesn't exist.`
Return values If the system call succeeds the return value is 0. If the system call fails the return value is one of the following errno values:
`-ENOKEY` | `No matching key was found.`
`-EKEYREVOKED` | `The key has already been revoked.`
`-EACCES` | `The named key exists, but is not writable by the calling process.`
Remarks The caller must have write permission on a key to be able revoke it.