sigstack(2) on FreeBSD
The text 5472735fc3d7, as FreeBSD 6.3-RELEASE, FreeBSD 6.2-RELEASE, FreeBSD 6.1-RELEASE, FreeBSD 6.0-RELEASE, FreeBSD 5.5-RELEASE, FreeBSD 5.4-RELEASE, FreeBSD 5.3-RELEASE, FreeBSD 5.2.1-RELEASE, FreeBSD 5.2-RELEASE, FreeBSD 5.1-RELEASE shipped it.
set and/or get signal stack context