semantics via posix_spawn(3), and it immediately execs a new internal
binary, systemd-executor, that receives the configuration to apply
via memfd, and sets up the process before exec'ing the target
- executable.
+ executable. The systemd-executor binary is pinned by file descriptor
+ by each manager instance (system and users), and the reference is
+ updated on daemon-reexec - it is thus important to reexec all running
+ manager instances when the systemd-executor and/or libsystemd*
+ libraries are updated on the filesystem.
* Most of the internal process tracking is being changed to use PIDFDs
instead of PIDs when the kernel supports it, to improve robustness