Re: [PATCH] Fix mmap_kmem (was: [question] What's the difference between /dev/kmem and /dev/mem)

Steven Rostedt
2005-08-12T17:33:20Z

On Fri, 12 Aug 2005, Arjan van de Ven wrote:
> > Again, I'm asking to have it turned into a config option. Even default to
> > off. I understand that /dev/kmem shouldn't be in a production machine.
> > There's no reason for it. But it is nice to have when debugging the
> > kernel. I'll make the changes if need be, to make this into a config
> > option (placed in the kernel debug section). I'll even maintain it to
> > keep it working. But I don't want yet another thing I need to write
> > myself for debugging the kernel.
>
> and /proc/kcore doesn't cut it for you?

I don't know. Can I mmap kcore, set up a function that I want to try out
before putting in the kernel, have it modify the variables that are
mmapped, and see if all works?

Also, I've only used /proc/kcore with gdb, I never wrote my own core
parsing programs.

I like to do some strange things when adding stuff to the kernel, and
mapping /dev/mem to get to kernel globals from user space was one of
them. I didn't just monitor, I did modify things as well. But this was
all for R&D and testing. Never for the final product, so that's why I
don't mind a config option, even under kernel debug.

-- Steve