Development/Howto/Report Kernel Bugs

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Reporting Kernel bugs

This document describes how to provide useful information in kernel bug reports.

1 Introduction
2 Kernel bug report format
3 In case of a boot time panic
4 References

[edit] Introduction

The form below is the suggested way to make kernel bugs reports on bugzilla, or even by e-mail. Note that you aren't obliged to use the bug reporting format, it is provided as a guide to the kind of information that can be useful to developers.

[edit] Kernel bug report format

One line summary of the problem (on bugzilla, this is the 'summary' field):
Full description of the problem/report:
Keywords (i.e., modules, networking, kernel):
Mandriva kernel version (from /proc/version ):
Most recent Mandriva kernel version which did not have the bug:
Output of Oops.. message (if applicable)
Steps to reproduce (you can append shell scripts or little programs which triggers the bug)
Environment
1. Mandriva distribution version (from /etc/mandriva-release)
2. Processor information (from /proc/cpuinfo ):
3. /etc/modprobe.conf
4. Module information ( lsmod ):
5. Loaded driver and hardware information ( /proc/ioports, /proc/iomem )
6. PCI information ( lspci -vvv as root)
7. SCSI information (from /proc/scsi/scsi )
8. Other information that might be relevant to the problem (please look in /proc, /sys and include all information that you think to be relevant):
Other notes, patches, fixes, workarounds:

[edit] In case of a boot time panic

A boot time panic is an error at boot that ends with messages similar to:

 mounting root filesystem /dev/root with flags noatime
 mount:error 19 mounting ext3 flags noatime
 switching to new root
 error opening /dev/console!!!:2
 umounting old /proc
 umounting old /sys
 switchroot mount failed:22
 initrd failed
 kernel panic - not syning

In this case we will need:

Screen capture until the panic (use a camera, a SerialConsole, or a pencil).

  Be sure to include anything from line Red Hat nash version 4.2.17mdk starting
  up to the line Kernel Panic - notsyncing : Attempted to kill init!
  Unfortunately since the machine panicked in graphic mode you will probably not be able to scroll up using Shift-PgUp
  so you will have to edit the bootloader command line and add the words vga=ask, 
  then choose a suitable text mode (the one with the more lines available)

stdout and stderr from mkinitrd invocation, use the following command:

sh -x /sbin/mkinitrd -v -f /boot/initrd-X.Y.Z-Wmdv.img X.Y.Z-Wmdv > /tmp/mkinitrd.log 2>/tmp/mkinitrd.err where X.Y.Z-Wmdv is the version of the kernel you are installing. To do the above you will need to boot from an older kernel, if you have a working one, or from the rescue CD.