From: Mark Wielaard <mark@klomp.org>
To: Phil Muldoon <pmuldoon@redhat.com>
Cc: frysk@sourceware.org
Subject: Re: frysk-core/frysk/proc Breakpoint.java IsaIA32. ...
Date: Wed, 22 Aug 2007 18:08:00 -0000 [thread overview]
Message-ID: <1187806056.3759.27.camel@dijkstra.wildebeest.org> (raw)
In-Reply-To: <46CC5226.8040607@redhat.com>
Hi Phil,
On Wed, 2007-08-22 at 10:11 -0500, Phil Muldoon wrote:
> > Fixes bug #3676
> > * Breakpoint.java (stepDone): Only set if still installed.
> > (isInstalled): new method.
> > (toString): Prettify.
> > * IsaIA32.java (isTaskStepped): Reset flag.
> > * IsaX8664.java (isTaskStepped): Likewise.
> >
> As we talked about on irc, and in addition to looking at this code in
> preparation for hardware watchpoints, can I make a small recommendation
> here?
>
> isTaskStepped(task) is a query, and should imo not be altering any debug
> registers after the fact.
>
> Can I propose a split into:
>
> isTaskStepped(task) and setTaskStepped(task)
>
> Does that make better sense?
That does make sense. Although I don't know if someone really needs
setTaskStepped(), so I wouldn't introduce it unless there was a real
usage for it. The reason why the flag is reset here is mentioned in the
original patch email:
http://sourceware.org/ml/frysk/2007-q1/msg00024.html
> There is one thing that changed in the semantics of Isa.isTaskStepped()
> for x86 and x86_64 (and Ia32On64 has been added). That is that the
> stepping flag in the d6 register is being reset because "[the d6]
> register is never cleared by the processor and must be cleared by
> software after the contents have been read". This means that we are now
> doing a inferior visible change, but I don't see any way to get around
> this. If the inferior would be using instruction stepping itself there
> would be all kinds of interesting issues anyway.
I do agree this might not be the most ideal place to reset this flag
though. Maybe it should be moved into LinuxTask.sendContinue()?
Cheers,
Mark
next prev parent reply other threads:[~2007-08-22 18:08 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20070115134847.31787.qmail@sourceware.org>
2007-08-22 15:11 ` Phil Muldoon
2007-08-22 18:08 ` Mark Wielaard [this message]
2007-08-22 21:47 ` Phil Muldoon
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1187806056.3759.27.camel@dijkstra.wildebeest.org \
--to=mark@klomp.org \
--cc=frysk@sourceware.org \
--cc=pmuldoon@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).