iovisor / iovisor/bcc

Can a USDT found via `tplist` be fed into `trace`?

Open
#3,863 10 comments 0 reactions 0 assignees View on GitHub
Dominant language
C
Stars
22.7k
Forks
4.1k
Avg merge
10d 4h
Merged PRs (30d)
3

Description

I ran:
```
$ tplist -l python3
/usr/bin/python3 python:gc__start
/usr/bin/python3 python:gc__done
/usr/bin/python3 python:audit
/usr/bin/python3 python:import__find__load__start
/usr/bin/python3 python:import__find__load__done
/usr/bin/python3 python:line
/usr/bin/python3 python:function__return
/usr/bin/python3 python:function__entry
```

Alike #1749, should I be able to trace one of the probes by directly running as the following command?
```
trace -p $(pgrep -n python3) u:python:function__entry
```
If I do so, I get the following message:
```
could not determine address of symbol b'function__entry'
```

Should the syntax be different? I can update the documentation accordingly so it is more clear for future users
Is the syntax of the trace query described somewhere? Or do we have only the examples available?

I have taken a look at the `trace` script, but it is not clear to me how it should handle binaries

Contributor guide

No contributing guide indexed for this repository

Research direction

Start by reproducing the tplist output and the trace command, then read the trace script to determine how user-space probes are resolved. Compare the accepted probe syntax with the Python USDT names shown; the work is done when the correct invocation or limitation is established and the relevant usage documentation is clear.

Written by the indexing model from the issue text.

Assessment

Tech stack
linux, python
Domain
cli, devtools, operating-systems
Issue type
Documentation
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
35/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.