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Date: Mon, 05 Nov 2001 08:25:00 -0000
From: Quality Quorum <qqi@world.std.com>
To: Steven Bauer <bauer@atlas.lcs.mit.edu>
cc: <gdb@sourceware.cygnus.com>
Subject: Re: x86 hardware breakpoint question
In-Reply-To: <20011115125927.B3449@atlas.lcs.mit.edu>
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On Thu, 15 Nov 2001, Steven Bauer wrote:

> Quick question, does gdb support hardware breakpoints on
> x86 architectures?  I have been trying to get them to work keep
> getting an unknown error.
>
> (gdb) hbreak   *0x80485d9
>
> ....
>
> warning: Cannot insert breakpoint 3:
> Error accessing memory address 0x80485d9: Unknown error 4294967295.
>
>
> One other question, is there any way to have breakpoints enabled
> when an exec occurs.  What I would like to do is continue through the
> exec getting the sigtrap if the new process is loaded, delete old
> breakpoints, load the symbols for the new process, and eventually
> reset breakpoints once main is hit.  The reason I want this is that
> the exec could fail, in which case I want the original breakpoints to
> still be in place.  If I remove all the breakpoints before the
> exec, continue, and the exec fails, I miss all the functions I
> originally had breakpoints set for.

First, it has to be supported be stub, current stub does not do it.
Plus, there are few things to be improved on the gdb side.


>
> Thanks,
> Steve
>
>
>
>

Thanks,

Aleksey