kernel config -- Re: Debian Investigation Report after Server Compromises

[Alvin Oga <aoga@ns.Linux-Consulting.com>]

hi ya benedict

On Wed, 3 Dec 2003, Benedict Verheyen wrote:

> > I'm one of those who's got all his systems on safe kernels, even if this
> > means I don't have full use.  NICs on one box aren't supported by
> > 2.4.18, and building 2.4.23 is turning into a bitch.
> 
> Is there a page anywhere (if not, there should be one) or info on what
> type of patches are added to a debianized kernel and where to find them.

i think you can do the following to see what your kernel does

uname -a 
	- lets say it says 2.4.22-foo

to get a list of modules it supports
	ls -la /lib/modules/2.4.22-foo
	
to get a list of options built into the kernel

	cd /usr/local/src
	wget kernel.org/.....2.4.22.tar.gz
	tar zxvfp 2.4.22.tar.gz
	cd linux-2.4.22	( virgin kernel from kernel.org )
	make xconfig
		- save it's default .. do NOT change anything
		mv .config .config.defaults

	make oldconfig
		- should create a .conf of your kernel

	diff .config .config.defaults
		- to see the differences 

- dont know if that still works.. havent tried it in years..

- its 100x easier/faster to make your own kernel than to figure out
  what they did to it


> 1. Either this info just isn't there because you don't need cramfs
>    for an initrd

initrd is NOT needed ..
	- not needed if all the options are built intot he kernel
	- not needed if your /  is under the 1024 cyl boundry

	initrd is used primarily to boot your system, when the kernel
	you're trying to use doesnt have all the options defined

	( you cant read the scsi disk till you have a kernel to read
	( the kernel off the scsi disk .. the typical catch-22 problem 
		- build the scsi drivers into your custom kernel and boot
		it and that problem goes away

c ya
alvin