mmlr's blog

Usually when you arrive in KDL (Kernel Debugging Land) it means that something bad happened. KDL provides a lot of tools to investigate what might have taken place. Still, it is quite possible that, even though you have that arsenal of tools available, you may not be able to immediately make sense of what is going on. In that case you ideally either continue debugging yourself or you write up a nice bug report over at the Haiku bug tracker so that someone else can take a closer look.

Puh, time has passed again and the signals from my side might have been a bit confusing with only the last blog post in mind. Therefore I'm going to explain what provoked that flurry of seemingly unrelated commits and how the KeyStore API is coming along.

So what is going on right now in the time I spend on my Haiku contract? For the past two and a half weeks I've had my mind wrapped around various parts of the kernel. Things started out at BeGeistert and the coding sprint following it. The nice thing about the coding sprint is that you spend a lot of time with very knowledgeable people and can therefore tackle things that you would usually shy away from. In this case, Ingo Weinhold and I were seeing some random memory corruption problems and an apparent memory/pages leak. So we started investigating those by adding more debug functions into the relevant parts.

There's plenty of ways to introduce subtle bugs into your code that give you a hard time finding and fixing. In this post I'd like to introduce you to malloc_debug, a heap implementation with added debug helpers, and outline how it can be used to find some of these problems.