Re: [PATCH] KDB: Fix usability issues relating to the 'enter' key.

From: Andrei Warkentin
Date: Tue Feb 28 2012 - 12:24:41 EST


Hi Jason,

----- Original Message -----
> From: "Jason Wessel" <jason.wessel@xxxxxxxxxxxxx>
> To: "Andrei Warkentin" <andrey.warkentin@xxxxxxxxx>
> Cc: kgdb-bugreport@xxxxxxxxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, "Andrei Warkentin" <andreiw@xxxxxxxxxx>
> Sent: Tuesday, February 28, 2012 8:53:20 AM
> Subject: Re: [PATCH] KDB: Fix usability issues relating to the 'enter' key.
>
>
> I think we are a lot closer this time. I attached a new patch based
> on your prior version.
>
> This is the wrong place to do this. The cleanup needs to get
> executed
> any time you are going to leave kdb_main(), because there are a few
> conditions like cpu switch, and transition to kgdb where you would
> leak the enter code on to the buffer handler without ever returning
> to
> the OS. Also if you did not set CONFIG_KDB_KEYBOARD your patch did
> not compile properly. We could have fixed this by moving the code to
> the input cleanup in kgdboc, but this is not needed at all if you
> take a look at the revised version.
>

Oh I see now. Okay. I'll keep this in mind.

> >
> >
> > Fixed previous regression where if kbd was not used
> > to 'g' + ENTER, the cleanup code would hang.
>
>
> Was this a regression in the out of tree code or something in the
> mainline kdb?

The first patch I sent out didn't have the kbd_last_ret bit. I found this
while using netkgdb and kgdboc together, but I'm certain this would
also apply if you ran kgdboc=ttyS0,kbd and broke in/resumed from serial
without ever touching the i8042 keyboard.

>
> I added kbd_last_ret = 0; right here so this cannot get triggered a
> second time if the kdb main loop is entered and exited without going
> to the shell (which can happen on a soft single step operation on
> some archs).
>

Looks good to me! I gave it a spin as well.

Acked-by: Andrei Warkentin <andrey.warkentin@xxxxxxxxx>

A
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