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Re: Reset breakpoint after load?
- From: Daniel Jacobowitz <dan at codesourcery dot com>
- To: Michael Snyder <msnyder at vmware dot com>
- Cc: Dave Korn <dave dot korn dot cygwin at googlemail dot com>, Jie Zhang <jie dot zhang at analog dot com>, "gdb at sourceware dot org" <gdb at sourceware dot org>
- Date: Thu, 21 Jan 2010 16:19:59 -0500
- Subject: Re: Reset breakpoint after load?
- References: <4B5560E0.3080901@analog.com> <4B582A02.2040501@gmail.com> <4B589CF2.2040304@vmware.com>
On Thu, Jan 21, 2010 at 10:29:06AM -0800, Michael Snyder wrote:
> >On 19/01/2010 07:36, Jie Zhang wrote:
> >
> >>gdb-comm.exp sets breakpoints on exit and abort before load. The problem
> >>is that GDB tries to skip prologue according to what it reads from
> >>memory, which might contain random data since the executable has not
> >>been loaded into memory. In my case, sometimes skip_prologue might skip
> >>one or two more instructions, which happens to be an exception
> >>instruction and will trap the processor into an exception event loop
> >>after running the executable before hit the breakpoints.
I've had this problem on a MIPS target, too.
> I don't believe that gdb can tell when the (remote) inferior
> is started. All gdb knows is that target remote is started.
> Thus, if we connect to target remote and then load the image,
> there is an interval during which gdb will attempt to read
> the prologue bytes from un-initialized target memory.
>
> Seems to me, that interval is a bad time to set breakpoints.
The problem isn't just breakpoints set during the interval, but also before
target remote. We adjust the breakpoints after target remote.
GDB doesn't know whether we're going to need to load. Maybe it should
be an option to target remote to load automatically? I don't know,
that's a little strange.
--
Daniel Jacobowitz
CodeSourcery