From: Andrew Cagney <cagney@redhat.com>
To: Mark Wielaard <mark@klomp.org>
Cc: frysk@sourceware.org
Subject: Re: [patch] Don't crash on stepping "bad frame"
Date: Fri, 29 Feb 2008 16:03:00 -0000 [thread overview]
Message-ID: <47C82C87.4090600@redhat.com> (raw)
In-Reply-To: <1204298035.7826.37.camel@dijkstra.wildebeest.org>
Mark,
Interesting work-around; I'll add some comments to explain exactly
where/when this senario occures. And where/when it doesn't. For
instance a step-out through a sigalt stack, whith a bad unwind, will
make the wrong decision.
Andrew
Mark Wielaard wrote:
> Hi,
>
> While working on #5259 I noticed that the stepping engine crashes and
> burns on x86_64 when a bad frame without unwind info is being stepped
> into. This patch handles that case gracefully. And you can now safely
> next through simple examples programs like funit-hello as we did in the
> last demo - you can still drop into the wrong frame till #5259 is fixed
> though.
>
> frysk-core/frysk/stepping/ChangeLog
> 2008-02-29 Mark Wielaard <mwielaard@redhat.com>
>
> * StepOverTestState.java (handleUpdate): Don't crash when there is
> a bad outer frame.
>
> Committed,
>
> Mark
>
> --- a/frysk-core/frysk/stepping/StepOverTestState.java
> +++ b/frysk-core/frysk/stepping/StepOverTestState.java
> @@ -86,6 +86,16 @@ public class StepOverTestState extends State {
> * it exits - success!
> */
> Frame frame = newFrame.getOuter();
> + if (frame == null)
> + {
> + // But urgh... Where did our outer frame go...
> + // We need to just try to keep stepping till we are
> + // able to get a solid frame again.
> + tse.getSteppingEngine().continueForStepping(this.task,
> + true);
> + return this;
> + }
> +
> tse.getSteppingEngine().setBreakpoint(this.task,
> frame.getAddress());
> return new StepOverState(this.task);
>
>
>
next prev parent reply other threads:[~2008-02-29 16:03 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-02-29 15:14 Mark Wielaard
2008-02-29 16:03 ` Andrew Cagney [this message]
2008-03-02 12:34 ` Mark Wielaard
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