Re: [BUG] perf probe can't insert return kprobe

From: David Ahern
Date: Fri Jan 09 2015 - 10:04:47 EST


On 1/9/15 7:55 AM, Jiri Olsa wrote:
hi,
I couldn't use following perf command to insert return probe:

# perf probe -a fork_exit=do_fork%return
Added new event:
Failed to write event: Invalid argument
Error: Failed to add events.


I'm pretty sure I used this command before, so seems like
it's broken. I can still use debugfs tracing interface to
do that:
# echo 'r:do_fork_entry do_fork' > kprobe_events

I used Arnaldo's latest perf/core and FC20 kernel:

# uname -a
Linux krava 3.17.7-200.fc20.x86_64 #1 SMP Wed Dec 17 03:35:33 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
# ./perf version
perf version 3.18.g6a7d78


If you want to bisect it the perf-probe command works for me on FC20, 3.17.7-200.fc20.x86_64 with perf from 3.12 (my local modified version is based on 3.12).

David

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