RE: [patch] MI telnet service

Abid, Hafiz
2012-07-24T16:17:41Z

> -----Original Message-----
> From: Marc Khouzam [mailto:marc.khouzam@ericsson.com]
> Sent: Saturday, July 14, 2012 8:37 PM
> To: Abid, Hafiz; Eli Zaretskii
> Cc: gdb-patches@sourceware.org
> Subject: RE: [patch] MI telnet service
>
> > > -----Original Message-----
> > > From: gdb-patches-owner@sourceware.org [mailto:gdb-patches-
> > > owner@sourceware.org] On Behalf Of Eli Zaretskii
> > > Sent: Thursday, July 12, 2012 2:29 PM
> > > To: Abid, Hafiz
> > > Cc: gdb-patches@sourceware.org
> > > Subject: Re: [patch] MI telnet service
> > >
> > > > From: "Abid, Hafiz" <Hafiz_Abid@mentor.com>
> > > > Date: Thu, 12 Jul 2012 11:20:36 +0000
> > > >
> > > > This patch provides implementation of telnet service. This is
> based
> > > on initial work by Grigory
> Tolstolytkin.(http://sourceware.org/ml/gdb-
> > > patches/2011-11/msg00466.html)
> > >
> > > Thanks. A few comments about the documentation part:
> > >
> > > > +Start a telnet service on the given port. After the service is
> > > started,
> > > ^^
> > > Two spaces between sentences, please (here and elsewhere, including
> in
> > > comments to C code).
> > >
> > > > +user can connect to the gdb via telnet and execute CLI commands
> in
> > > ^^^
> > > "@value{GDBN}" instead of a literal "gdb".
> > >
> > > > +new one. For telnet service to work, @value{GDBN}
> > > > +should be configured with --enable-gdbmitel=yes.
> > >
> > > Use @option for options, like this: @samp{--enable-gdbmitel=yes}.
> > >
> > > Btw, why does it make sense to require a configure-time option for
> > > this feature? why not include it by default?
> >
> > It just felt a bit safer to keep it optional. If community thinks
> that
> > it is useful feature then I see no problem in making it available by
> default.
>
> I think it makes sense to have a way to turn off this feature. Some
> people may
> think it is a security issue to have this port open and wish to keep
> the feature
> completely disabled. However, if Eclipse is to make use of this
> feature, it
> has to be enabled in GDB, and it would complicate things greatly if we
> had to
> ask the user to re-compile GDB to enable this setting. It would be
> much nicer
> if it worked directly in the GDB distributed with their linux box.
> Therefore, I hope we can have this setting enabled by default.
>
> I tried out the patch with and without Eclipse and it looks quite good!
> Here are some issues I found:
>
> - If I set a tty (-inferior-tty-set), GDB exits (or crashes?) when
> sending an
> empty command (just pressing enter) over telnet. Eclipse uses a tty
> for the
> inferiors.
Can you kindly list the steps to reproduce this crash. I tried but it worked ok for me.

>
> - For every command sent over telnet, there is a printout in the orinal
> GDB
> saying "Switching to interpreter "console"." Not a big deal, but maybe
> something to remove.
>
> - starting the telnet service, connecting to it, and then stopping the
> service (-stop-telnet-service), does no seem to clean up the port
> propertly
> and I see:
> ^error,msg="Error: port 9996 can't be bind"
>
> - If I start GDB in CLI mode, and try to use the telnet service, GDB
> segfaults
> after the first command is sent over telnet. I know this service is
> not
> currently meant to be used with the CLI mode, but it should not crash
> :)
> I personally think this would be cool to have even for CLI mode, but if
> it
> won't be for now, maybe the telnet service should be disabled in that
> case.
>
> I realize this is a first and important step, but it will be even nicer
> when the telnet service supports tab-completion and command-history.
>
> This is very exciting! Thanks!
>
> Marc
Thanks for taking time to test.

Regards,
Abid