From: Jonathan Larmour <jlarmour@redhat.com>
To: Mark Salter <msalter@redhat.com>
Cc: john@talisker.demon.co.uk, ecos-discuss@sourceware.cygnus.com
Subject: Re: [ECOS] gdb 'next' problem with i386 HAL
Date: Wed, 05 Sep 2001 08:32:00 -0000 [thread overview]
Message-ID: <3B964586.739C5116@redhat.com> (raw)
In-Reply-To: <200108291346.f7TDkrZ06511@deneb.localdomain>
Mark Salter wrote:
>
> >>>>> John Gumb writes:
>
> > The problem only occurs when 'nexting' over a function call.
[snip]
> > The trouble is, the return address isn't there. I had a poke around and it actually is 16 bytes further down the stack. [snip]
>
> I think this is a problem in the HAL code. The HAL is passing
> the wrong SP value to GDB. The problem is that the HAL stub
> uses the same stack as the app being debugged. The HAL should
> be switching to a dedicated GDB stub stack.
Actually the problem is that on the x86 16 bytes automatically get saved on
the stack by the CPU before we have a chance to do anything about it. The
solution is to adjust the SP stored by the __default_exception_vsr into the
HAL_Saved_Registers struct by 16.
I'll check something in to hopefully fix it that should be in anon cvs some
time soon.
Jifl
--
Red Hat, Rustat House, Clifton Road, Cambridge, UK. Tel: +44 (1223) 271062
Maybe this world is another planet's Hell -Aldous Huxley || Opinions==mine
next prev parent reply other threads:[~2001-09-05 8:32 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-08-29 6:42 John Gumb
2001-08-29 6:47 ` Mark Salter
2001-09-05 8:32 ` Jonathan Larmour [this message]
2001-09-05 8:44 ` Mark Salter
2001-09-05 8:55 ` Jonathan Larmour
2001-09-05 9:33 ` Mark Salter
2001-09-05 14:16 ` Jonathan Larmour
2001-09-05 14:59 ` Mark Salter
2001-09-05 15:17 ` Jonathan Larmour
-- strict thread matches above, loose matches on Subject: below --
2001-08-24 7:19 Patrick O'Grady
2001-08-23 2:54 John Gumb
2001-08-22 12:20 Allan Young
2001-08-15 15:08 John Gumb
2001-08-16 6:44 ` Jonathan Larmour
2001-08-17 0:31 ` Boris V. Guzhov
2001-08-17 6:17 ` Jonathan Larmour
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