valgrind currently doesn't support Linux ioctls used on PTP hardware clock devices and Pulse-Per-Second devices. They are typically used by various NTP and PTP implementations (e.g. ntpd, linuxptp, chrony).
Created attachment 121155 [details] Add support for Linux Pulse-Per-Second ioctls
Created attachment 121156 [details] Add support for Linux PTP HW clock ioctls
Committed as bba186064e905d6fbed6d18cc2f66f4ec78e2c1d. Thanks for the patches.