[PATCH 0/4] KDB: Fix dmesg command

[Anton Vorontsov <anton.vorontsov@linaro.org>]

Hi all,

The dmesg command appears to be broken after the printk rework. The old
logic in the kdb code makes no sense in terms of current printk/logging
storage format, and KDB simply hangs forever upon entering 'dmesg'
command.

The first patch revives the command by switching to kmsg_dumper iterator.
As a side-effect, the code is now much more simpler.

A few changes were needed in the printk.c: we needed unlocked variant
of the kmsg_dumper iterator, but these can surely wait for 3.6.

It's probably too late even for the first patch to go to 3.5, but
I'll try to convince otherwise. :-) Here we go:

- The current code is broken for sure, and has no hope to work at
  all. It is a regression;
- The new code works for me, and probably works for everyone else;
- If it compiles (and I urge everyone to compile-test it on your
  setup), it hardly can make things worse.

Thanks!

--
 include/linux/kmsg_dump.h      |   16 +++++++
 kernel/debug/kdb/kdb_main.c    |   91 +++++++++++++++-------------------------
 kernel/debug/kdb/kdb_private.h |    1 -
 kernel/printk.c                |   83 +++++++++++++++++++++++-------------
 4 files changed, 104 insertions(+), 87 deletions(-)

-- 
Anton Vorontsov
Email: cbouatmailru@gmail.com