Re: Feature Request

[Jonas Maebe <jonas.maebe@elis.ugent.be>]

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On 12 Nov 2013, at 18:02, Mark Manning wrote:

> So, I would like to request a feature that will allow GDB to simply
> single step opcodes anywhere within the process space owned by the
> application being debugged even if there is no debug symbols
> associated with it.

It already does that. Just use "si" (or "stepi") rather than "step" or "next". It can be useful to have "display/i $pc" active when doing so, so you can see what's the next instruction to be executed.


Jonas
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Subject: Re: Feature Request
From: Jonas Maebe <jonas.maebe@elis.ugent.be>
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On 12 Nov 2013, at 20:59, Mark Manning wrote:

> actually no, it wont.  it will not execute code that does not have
> debug associated with it.  ... for example (in ascii art)

It's definitely unrelated to whether or not there is debug information for that code. I debug machine code without associated debug information using gdb all the time. It is however possible that the size of code sections is taken into account.


Jonas
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From: Jonas Maebe <jonas.maebe@elis.ugent.be>
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Subject: Fwd: Feature Request
Date: Tue, 12 Nov 2013 20:34:00 -0000
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From: Mark Manning <mark4th@gmail.com>
Date: 12 Nov 2013 21:15:12 GMT+01:00
To: Jonas Maebe <jonas.maebe@elis.ugent.be>
Subject: Re: Feature Request

yes. for example i just performed the following steps

1: strip my executable
2: gdb the stripped executable
3: set breakpoint at a known location thatn when single stepped will
jump to code that was written in during execution prior to hitting the
breakpoint
4: single step one opcode.  This results in "Can not access address 0".
5: disp /3i $pc.  this shows the program counter at the expected code
6: stepi.  this gives "can not find bounds of current function" and
displaying a disassembly from the program counter shows that nothing
was executed.



On Tue, Nov 12, 2013 at 3:03 PM, Jonas Maebe <jonas.maebe@elis.ugent.be> wrote:
> 
> On 12 Nov 2013, at 20:59, Mark Manning wrote:
> 
>> actually no, it wont.  it will not execute code that does not have
>> debug associated with it.  ... for example (in ascii art)
> 
> It's definitely unrelated to whether or not there is debug information for that code. I debug machine code without associated debug information using gdb all the time. It is however possible that the size of code sections is taken into account.
> 
> 
> Jonas



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