KernelNewbies:

So, you think you've found a Linux Kernel bug? Maybe your dmesg has an oops message in it, or your wireless doesn't work after an upgrade? Maybe your new whizbang USB device doesn't work on any kernel? This is the place to get directions on how to report bugs to kernel engineers.

Identify the problematic subsystem

The Linux kernel is a very complex operating system, with many different individual subsystems. Each subsystem (like USB or SCSI) has its own [http://lxr.linux.no/source/MAINTAINERS maintainer], and usually its own [http://vger.kernel.org/vger-lists.html mailing list]. Identifying which subsystem might be causing your issues increases your chances of getting your bug report to the right person who can fix it. Simply posting to the generic linux-kernel mailing list (LKML) may cause your bug report to be lost in the noise.

There are several tools you can use to figure out what's wrong with your system. The simpliest is the command-line tool dmesg, which displays the Linux log file from the last time your computer booted. If you want to see messages prior to your last boot, you can look in the individual log files in /var/log. Some useful log files are /var/log/kern.log (the Linux kernel log file) and /var/log/Xorg.0.log (the Xserver log file). Things to look for are warnings, failures, or oops messages.

Oops messages

An oops is a message that happens when a bug is triggered. An oops message looks [http://marc.info/?l=linux-kernel&m=135048168712624&w=2 something like this]. If you want to learn how to decode an oops message, there's a good tutorial in the "Oops Messages" section of the Linux Device Drivers, [http://lwn.net/Kernel/LDD3/ Chapter 4]. Basically, you want to look at the "Call Trace" portion of the oops message and see which subsystems were in the path of the oops. In the linked example, the oops takes place somewhere in the security apparmor layer.

Identify who to notify

Once you know the subsystem that is causing the issue, you should send a bug report. Some maintainers prefer bugs to be reported via the [bugzilla.kernel.org kernel.org Bugzilla], while others prefer that bugs be reported via the subsystem mailing list.

Figure out where you think the problem is.

Step 2

http://www.kernel.org/doc/linux/REPORTING-BUGS Send email to the mailing list of choice. You can also file a bugzilla bug, although some maintainers prefer the mailing list.

Step 3

Try to reproduce the bug on the latest stable kernel. Need directions for kernel installation.

http://www.chiark.greenend.org.uk/~sgtatham/bugs.html http://www.catb.org/~esr/faqs/smart-questions.html

KernelNewbies: BugReporting (last edited 2012-10-18 02:24:47 by SarahSharp)