public inbox for systemtap@sourceware.org
 help / color / mirror / Atom feed
From: fche@redhat.com (Frank Ch. Eigler)
To: Matt Vibrys <vibrys@o2.pl>
Cc: systemtap@sourceware.org
Subject: Re: non-working .return probepoint from modules
Date: Thu, 16 Dec 2021 21:33:39 -0500	[thread overview]
Message-ID: <87mtl0aqhn.fsf@redhat.com> (raw)
In-Reply-To: <umt4a6h0tpov.fsf@o2.pl>


>> The output below provides function calls, but it's silent about it's
>> returns. Why so?:

Good question, I wonder too!

>> gmm@MY-HOST:~/user$ sudo /opt/systemtap-4.6/bin/stap -vv /home/gmm/user/scripts/drm.stp
>> Systemtap translator/driver (version 4.6/0.176, non-git sources)
>> [...]

This is good, it contains the module-insertion fix PR28557.
The stap console trace looks okay.

> For better insight I've used drm module drm_ioctl function
> instead. The problem persists, ie .return "locks nothing":
> #+begin_src systemtap
>   probe module("drm").function("drm_ioctl")
>   {
>     printf("-->. %s %s %s\n", thread_indent(0), ppfunc(), $$parms);
>   }
>       
>   probe module("drm").function("drm_ioctl").return
>   {
>     printf("<--\n");
>   }

Would you consider rerunning a bit more pass-5 runtime side
tracing such as

% sudo stap -DDEBUG_KPROBES -DDEBUG_SYMBOLS [...]


- FChE


  reply	other threads:[~2021-12-17  2:56 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-15 20:51 Matt Vibrys
2021-12-16 17:38 ` Matt Vibrys
2021-12-17  2:33   ` Frank Ch. Eigler [this message]
2021-12-17 10:32     ` Matt Vibrys
2022-03-22  9:48       ` Matt Vibrys
2022-03-22 18:56         ` Frank Ch. Eigler
2022-04-06 12:37           ` Matt Vibrys

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87mtl0aqhn.fsf@redhat.com \
    --to=fche@redhat.com \
    --cc=systemtap@sourceware.org \
    --cc=vibrys@o2.pl \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).