Bug#703386: kmsg_dump is too eager to dump kernel log
Package: src:linux
Version: 3.2.39-2
Severity: important
Tags: patch upstream fixed-upstream
kmsg_dump can store the last kernel log messages using any of various
'dumper' functions in case of a crash, reboot, etc. Typically they
will be written to flash; on EFI systems they can be stored in EFI
variables.
Unfortunately, in 3.2 the log messages will be dumped on every
shutdown, reboot or kexec, which is undesirable:
- In the kexec case this is dangerous, as not all dumpers will work
during kexec. It's also redundant because there is an existing
mechanism for passing the old kernel log to the new kernel.
- In the normal shutdown/reboot case there is generally nothing
interesting to see after whatever was saved in the system log. Since
there is often only space for one kernel log dump, this also increases
the probability that a crash log will be overwritten before being
copied elsewhere.
Both of these have been fixed upstream and I intend to apply the fixes:
commit a3dd3323058d281abd584b15ad4c5b65064d7a61
Author: WANG Cong <xiyou.wangcong@gmail.com>
Date: Thu Jan 12 17:20:11 2012 -0800
kexec: remove KMSG_DUMP_KEXEC
commit c22ab332902333f83766017478c1ef6607ace681
Author: Matthew Garrett <mjg@redhat.com>
Date: Mon Mar 5 14:59:10 2012 -0800
kmsg_dump: don't run on non-error paths by default
Ben.
-- System Information:
Debian Release: 7.0
APT prefers unstable
APT policy: (500, 'unstable'), (500, 'testing'), (1, 'experimental')
Architecture: i386 (x86_64)
Foreign Architectures: amd64
Kernel: Linux 3.2.0-4-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_GB.utf8, LC_CTYPE=en_GB.utf8 (charmap=UTF-8)
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