Using debuginfo for `pid` provider probes

[thesamesam]

See also https://github.com/oracle/dtrace-utils/issues/84 and https://github.com/oracle/dtrace-utils/issues/96.

With SystemTap, one can attach based on line number and function name if debug info is available, AFAIK (https://blogs.oracle.com/linux/post/getting-started-with-systemtap-on-oracle-linux).

I see two usecases:

1. Printing argument or variable contents (not having to lookup which argument path is)
2. Being able to add a probe which I could already do via instruction offsets in a more friendly manner

[thesamesam]

I think stap supports this for the kernel side too but AFAIK CTF & BTF don't have the needed information and I think it has less value there anyway given there's more probes, so I think I'm only interested in the userland side.

[kvanhees]

On Wed, Aug 28, 2024 at 11:39:15AM -0700, Sam James wrote:

I think stap supports this for the kernel side too but AFAIK CTF & BTF don't have the needed information and I think it has less value there anyway given there's more probes.

The kernel is not an issue because we have access to the kallsyms info, which is (or should be) sufficient to resolve all kernel addresses in a stack trace.