Hacker News Reader

Comment by kumarvvr | Hacker News Reader

I see posts like this, this deep dive into the call stacks and am always humbled and reminded of the limits of my knowledge about computers and programs.

View on HN

These sort of bugs require a lot of knowledge about a) Windows Internals b) Tools to debug at that level. Most application-level programmers won't need nor are exposed to these.

However, if you are interested in knowing what is all involved, see; Advanced Windows Debugging by Mario Hewardt and Daniel Pravat - https://advancedwindowsdebugging.com/

Review of the book by Raymond Chen himself! - https://devblogs.microsoft.com/oldnewthing/20071218-01/?p=24...

Goes both ways, author probably knows little about FPGA programming, React or PyTorch.

Not a programmer?

I am, for 20 years now. I do embedded stuff too. Still.

I'm a bit surprised you don't run into things like this then :). Do you use GDB and the like at all?

Or do you mean all the windows specific stuff etc, I guess I was more imaging the call stack etc.

No insult was intended XD

I have done everything from desktop apps to web apps and a bunch in between. Regular debugging is good enough for me. Never had the need to go down into call stack level.

Even with embedded programming, regular C debugger has always been enough.

As someone who has debugged his fair share of tricky low-level issues, the parts that I find impressive in his blog posts are things such as "then we look at the bytes in memory and oh yeah, this looks like an exception record". I would usually not think to do that (or be able to recognise it as easily as I presume he did).

I assume it's mostly just something you learn to recognize after decades of poking at the same things. I remember being impressed with Thiago (Qt developer) being able to immediately tell if a pointer was heap allocated, invalid/unaligned, etc. until I spent more time poring over /proc/*/maps and in gdb. Never figured out how he could tell someone's Qt version just from an strace excerpt, though.

> Never figured out how he could tell someone's Qt version just from an strace excerpt, though.

Sonames might be a big clue? Otherwise, initialization order changes maybe? Sometimes there's enough file content in an strace to be able to see a strong indicator?

Those are just guesses, I do a lot more debugging with pcaps rather than straces. Although you do often want to determine which side of the syscall caused whatever you're seeing in the pcap.

Reply on news.ycombinator.com