Hacked GDB Dashboard Puts It All on Display | Hacker News Reader

Hacked GDB Dashboard Puts It All on Display

hackaday.com

101 pointsrcarmo20 comments

There are a lot of these types of tools already in the reverse engineering community (in order of lowest chance of breaking when you throw really weird stuff at it, in my experience):

GEF: https://gef.readthedocs.io/en/master/

PWNDBG: https://github.com/pwndbg/pwndbg

PEDA: https://github.com/longld/peda

They also come with a slew of different features to aid in RE/exploit dev, but many of them are also useful for debugging really weird issues.

Also if you don't need all the info these provide or just want to augment them, the tool you are looking for is "hook-stop" which allows you to execute a string of commands every time GDB pauses program execution.

I tried to promote gdb-dashboard a few days ago at HN but it did not fly.

gdb-dashbard is different from those reverse-engineering gdb-hacks in that, it is more for normal debugging with a better looking TUI than the default gdb tui interface.

gdb's support for python scripting made all these possible.

I like TUI but used to find it a bit flaky and inconsistent. I understand it's had a fairly recent code-level revamp.

GDB has also added Python extension support for it: https://sourceware.org/gdb/current/onlinedocs/gdb/TUI-Window...

It will be interesting to see if things like GDB Dashboard benefit from being implemented in this way in future.

I really like PWNDBG, as it goes. But I am trying to spend more time with the Ghidra debugger, which is ... kind of pants, but it's getting better and it's pretty nice to have everything in one place. :}

I miss SoftIce.

Anyone remember Periscope? It was a DOS debugger with the hardware button attached to the NMI pin on the chip to break in even if interrupts are disabled! It was awesome.

Still unequalled if you ask me, although gdb-dashboard comes pretty close.

EDIT: A quick bit of searching yielded a scanned copy of the manual courtesy of the os2museum.com:

https://www.os2museum.com/files/docs/periscope/periscope-man...

Being able to enter a debugger on NMI is great because now you can trigger the NMI from any set of hardware conditions too - you can connect logic gates to the address bus to decode a range of addresses, "and" it with the memory write assert pin or IORQ pin and now you have hardware breakpoints for a machine that didn't originally support it.

Nice! There is already a TUI in gdb albeit not as good looking. For more info, there is a quick talk about it and other niceties that you may not know about: https://www.youtube.com/watch?v=PorfLSr3DDI

This is a great presentation.

A similar project worth mentioning is Voltron, which can decorate your gdb session with accesory windows. (Use tmux for window layout).

No experience with this dashboard but looking forward to trying it.

Well that's a masterful stroke. I use GDB all the time not only for userspace but also the kernel. Its always sorta painful though for the exact reason that using tui and getting it to display variables, code, dissasembly, etc tends to require jumping through about 20 commands (usually via a gdb script) to see how the behavior is changing over time.

So, I'm not really sure why it took this long to catch up to the TUI debuggers from the late '80's (ala turbo debugger/etc).

Makes me want to integrate some of these windows with the kernel gdb scripts.

Dashboard has been around for a while. It helped me back when I learned GDB for the first time. Though you still have to learn the GDB commands, dashboard makes it a more visual experience. GDB felt clearer and more modern with it. It's better than the built-in TUI in my opinion.

"Some of my favorite interfaces are graphical."

However, accomplishing tasks with textual, batch-oriented interfaces seems easier to script, version, and integrate.

Those two are not mutually exclusive. You can make a GUI on top of batch / text interfaces. The interface is just the presentation.

Excellent point.

I remember the quite minimal CGDB interface. https://cgdb.github.io/

This is neat.

Can someone say what the "encrypt+" column to the left of the the Op code is in the screenshot?

"encrypt" is just the name of the function being debugged. The `+x` is the byte offset in that function.

It’s the instruction offset from a function entry point.

Looks nice, but usually I'm not very interested in the assembly instructions.

pwndbg and splitmind are fantastic out of the box too.

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