Re: [RFC PATCH 2/3] Add support to catch groups of syscalls.

[Sergio Durigan Junior <sergiodj at redhat dot com>]

On Monday, October 20 2014, Gabriel Krisman Bertazi wrote:

>> I'm not really comfortable with that (far more so than "catch syscall
>> open network-group").
>> If you want to require -g at the front, and thus disallow catching
>> both syscalls and syscall groups in the same command then that would
>> be fine with me.
>
> I really think we shouldn't disallow catching syscalls and syscalls
> group on the same command, no matter which syntax we pick.  GDB wiki
> says that GDB should be more permissive about command's syntax, in a
> sense that user shouldn't spend more time than needed to find out how a
> command works.  I think disallowing catching syscalls and groups on the
> same command would reduce expressiveness in this case.

I agree.

>> Still need a solution for listing them.  Arguably since we don't
>> provide a way to list syscalls (sigh, modulo the hack I showed, which
>> should be fixed so that it no longer works anyways :-)), providing a
>> way to list syscall groups is for a separate patch.  Kudos if you
>> still want to provide a way to list syscalls and groups though.
>
> So, definitively allowing "catch syscall -g" to list syscalls is not a
> good idea.  Sergio suggested off-list to use another option, maybe -lg
> to list syscall groups.  Then, a future patch could also extend catch
> syscall to list all syscalls using a -l option or something like that.
> Sergio, sorry if I got your suggestion wrong.

It is alright, I completely forgot I made that suggestion!  Thanks for
bringing it to the table.

Anyway, yeah, I guess '-lg' (or -list-groups) should be OK.

> OTOH, I might be over-thinking this simple stuff :).  I'm ok with the
> namespace (suffix) syntax, but I think we should go with "g:" (or even
> "group:network", if it's not too verbose) instead of "-group", to avoid
> the issue pointed out by Sergio with the exit_group syscall.

Yeah, maybe this is a bit over-thinking, but OTOH we are talking about
user interface, which cannot be changed easily after we make a release.

BTW, I like the idea of using the "g:" prefix, so I say "go for it" if
you think it is OK.

Sorry for not being able to comment more on the thread now, I am busy
with other things.  However, I think you covered all the issues with
your message, so you should be good to go as long as Doug has no other
comments.

Cheers,

-- 
Sergio
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