7. Miscellaneous (including macro packages and conventions)

THREAD-KEYRING

Section: Linux Programmer's Manual (7)
Updated: 2020-08-13
Index | Return to Main Contents

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.

COLOPHON

This page is part of release 5.10 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/.