答え1
https://www.kernel.org/doc/Documentation/ABI/stable/procfs-audit_loginuid
What: Audit Login Session ID
Date: 2008-03-13
KernelVersion: 2.6.25-rc7 1e0bd7550ea9 ("[PATCH] export sessionid alongside the loginuid in procfs")
Contact: [email protected]
Users: audit and login applications
Description:
The /proc/$pid/sessionid pseudofile is read to get the
audit login session ID of process $pid as a decimal
unsigned int (%u, u32). It is set automatically,
serially assigned with each new login.