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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  fork-
     ing, 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 cre-
     ated  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)

COLOPHON

     This page is part of release 4.16 of the Linux man-pages project.  A
     description of the project, information about reporting bugs, and the
     latest version of this page, can be found at
     https://www.kernel.org/doc/man-pages/.

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