A new version of kernel-package in Incoming at the time of writing adds support for creating a package which contains the Linux kernel debug image. This means the debugging information for the modules in the kernel image package, and the uncompressed vmlinux image. This builds on suggestions and code from Troy Heber, Theodore Y. Ts’o, and Dann Frazier.

As support for kexec/kdump support becomes more real, it will be very useful to be able to build kernels that have debugging information available, but not necessarily to install the debugging information on every single client system.

The .ko object files are stripped of the debugging information before they are placed in the standard linux-image installation package. However, before that, a copy of the vmlinux and unstripped .ko files are saved in a “debuginfo” package, and everything except for the debugging information is removed from them using objcopy --keep-only-debug. This means that if someone ends up with a crash dump, they can send it to a support engineer and only the support engineer needs to install the debuginfo package and use the “crash” utility to debug the crash dump. It’s also useful for developers, since the debuginfo information can be stored somewhere outside of /lib for storing its debug information, for example. This is useful for keeping the size of the root partition small, for those who keep / separate from /usr.

The locations used are compatible also with SystemTap, which provides free software infrastructure to simplify the gathering of information about the running Linux system. This assists diagnosis of a performance or functional problem. SystemTap eliminates the need for the developer to go through the tedious and disruptive instrument, recompile, install, and reboot sequence that may be otherwise required to collect data.

Also, I had to clear out some FUD about kernel-package from the ircbot dpkg on the OFTC Debian IRC channel, since someone had implied that kernel-package was some how obsolete. As can be seen, it is being actively developed, and features are being added apace.