Comment 0 for bug 1925216

[impact]

systemd prints messages that complain about system calls such as:

/lib/systemd/system/systemd-journald.service:33: Failed to parse system call, ignoring: pidfd_getfd

[test case]

boot bionic system with 4.15 kernel that does not support pidfd_getfd syscall

[regression potential]

any regression would prevent correct configuration of seccomp syscall filters, and/or failure to load/parse unit files that contain SystemCallFilter= directives

[scope]

this is needed only for b

this is fixed upstream by commit 13d92c6300edbb1369f97c2e1bef4c4096de8ddb which was included in v238, so this is fixed in focal and later

this is not needed for x as seccomp handling is completely different in that older release

[other info]

as the warning states, the invalid system call is ignored, which is the correct action, and the patch to fix this just changes the log to debug instead of warning (along with consolidation of several flag params into a single flag enum). Thus, no actual change in behavior should occur (other than logging the messages as debug instead of warning).