Re: [BUG] perf probe can't remove probes

[Masami Hiramatsu <mhiramat@kernel.org>]

On Thu, 26 Nov 2020 14:26:03 -0300
Arnaldo Carvalho de Melo <acme@kernel.org> wrote:

> Em Thu, Nov 26, 2020 at 09:21:25AM +0900, Masami Hiramatsu escreveu:
> > Hi Arnaldo,
> > 
> > On Wed, 25 Nov 2020 14:27:55 -0300
> > Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
> > 
> > > 
> > > Masami, have you stumbled on this already?
> > > 
> > > [root@seventh ~]# perf probe security_locked_down%return 'ret=$retval'
> > > Added new event:
> > >   probe:security_locked_down__return (on security_locked_down%return with ret=$retval)
> > > 
> > > You can now use it in all perf tools, such as:
> > > 
> > > 	perf record -e probe:security_locked_down__return -aR sleep 1
> > > 
> > > [root@seventh ~]# perf probe security_locked_down what
> > > Added new event:
> > >   probe:security_locked_down (on security_locked_down with what)
> > > 
> > > You can now use it in all perf tools, such as:
> > > 
> > > 	perf record -e probe:security_locked_down -aR sleep 1
> > > 
> > > [root@seventh ~]#
> > > 
> > > 
> > > [root@seventh ~]# uname -r
> > > 5.10.0-rc3.bpfsign+
> > > [root@seventh ~]# perf probe -l
> > >   probe:security_locked_down (on security_locked_down@git/bpf/security/security.c with what)
> > >   probe:security_locked_down__return (on security_locked_down%return@git/bpf/security/security.c with ret)
> > > [root@seventh ~]# perf probe -D '*:*'
> > > Semantic error :There is non-digit char in line number.
> > > 
> > >  Usage: perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]
> > >     or: perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]
> > >     or: perf probe [<options>] --del '[GROUP:]EVENT' ...
> > >     or: perf probe --list [GROUP:]EVENT ...
> > >     or: perf probe [<options>] --line 'LINEDESC'
> > >     or: perf probe [<options>] --vars 'PROBEPOINT'
> > >     or: perf probe [<options>] --funcs
> > > 
> > >     -D, --definition <[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT [[NAME=]ARG ...]>
> > >                           Show trace event definition of given traceevent for k/uprobe_events.
> > 
> > As you can see, "-D" is showing definition. Not delete. (*)
> > Delete is "-d" or "--del".
> 
> Yeah, I was in a hurry and looked at just the first line right after the
> command, didn't want to forget reporting it so sent the "bug" report,
> d0h, sorry about the noise, using -d or --del works.
> 
> But having both -d and -D, in retrospect, wasn't such a good idea :-\

Sorry for confusing :(

Hmm, would we better to remove -D and keep only --definition?
But it is already there, I think we should keep this option
for backward compatibility.

Thank you,



-- 
Masami Hiramatsu <mhiramat@kernel.org>