lttng-sessiond prints error message on wrong input
Whenever I call `lttng enable-event -k some_unsupported_event`, I receive the error message
PERROR [16145/16198]: create event ioctl: No such file or directory (in kernel_create_event() at kernel.c:208)
on the terminal where I started the session daemon as root.
Looking at the code in question (kernel.c:208), I find a switch(errno) block, where I had expected the "ENOSYS" case to be taken for the case of an unsupported kernel event, not the default, which reports the above error.
(I'm actually not sure who is responsible for setting the errno in this case. Would that come from the lttng kernel modules code that provides the ioctl() call ?)