[lttng-dev] Trying to understand use of lttng enable-event --kernel --userspace-probe=

[Brian Hutchinson]

Hi,

I'm trying to figure out how to use uprobes with lttng.

I can't use a normal uprobe for a line number just using the address I
want to probe obtained from objdump?  As in:

echo 'p /usr/local/bin/my_app:0x2c3a8' >>
/sys/kernel/debug/tracing/uprobe_events

... which isn't a function entry, it's just a line of code I want to probe on.

This link says it has to be elf or sdt:
https://lttng.org/man/1/lttng-enable-event/v2.11/#doc-opt--userspace-probe

So can I not probe on just a line of code by specifying an address???

It doesn't look like these methods above will do what I'm wanting to
do.  I've tried to find examples of using enable-event --kernel
--userspace-probe= but there doesn't appear to be many.

Thanks,

Brian