linux man page for thread-keyring

THREAD-KEYRING(7)					     Linux Programmer's Manual						 THREAD-KEYRING(7)

NAME
       thread-keyring - per-thread keyring

DESCRIPTION
       The  thread  keyring  is  a  keyring used to anchor keys on behalf of a process.  It is created only when a thread requests it.	The thread
       keyring has the name (description) _tid.

       A special serial number value, KEY_SPEC_THREAD_KEYRING, is defined that can be used in lieu of the actual  serial  number  of  the  calling
       thread's thread keyring.

       From  the  keyctl(1)  utility,  '@t'  can be used instead of a numeric key ID in much the same way, but as keyctl(1) is a program run after
       forking, this is of no utility.

       Thread keyrings are not inherited across clone(2) and fork(2) and are cleared by execve(2).  A thread keyring is destroyed when the  thread
       that refers to it terminates.

       Initially, a thread does not have a thread keyring.  If a thread doesn't have a thread keyring when it is accessed, then it will be created
       if it is to be modified; otherwise the operation fails with the error ENOKEY.

SEE ALSO
       keyctl(1), keyctl(3), keyrings(7), persistent-keyring(7), process-keyring(7), session-keyring(7), user-keyring(7), user-session-keyring(7)

Linux								    2017-03-13							 THREAD-KEYRING(7)