net: netconsole: Add continuation line prefix to userdata messages

Add a space (' ') prefix to every userdata line to match docs for
dev-kmsg. To account for this extra character in each userdata entry,
reduce userdata entry names (directory name) from 54 characters to 53.

According to the dev-kmsg docs, a space is used for subsequent lines to
mark them as continuation lines.

> A line starting with ' ', is a continuation line, adding
> key/value pairs to the log message, which provide the machine
> readable context of the message, for reliable processing in
> userspace.

Testing for this patch::

cd /sys/kernel/config/netconsole && mkdir cmdline0
cd cmdline0
mkdir userdata/test && echo "hello" > userdata/test/value
mkdir userdata/test2 && echo "hello2" > userdata/test2/value
echo "message" > /dev/kmsg

Outputs::

6.8.0-rc5-virtme,12,493,231373579,-;message
test=hello
test2=hello2

And I confirmed all testing works as expected from the original patchset

Fixes: df03f830d099 ("net: netconsole: cache userdata formatted string in netconsole_target")
Signed-off-by: Matthew Wood <thepacketgeek@gmail.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20240308002525.248672-1-thepacketgeek@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: netconsole: append userdata to fragmented netconsole messages

Regardless of whether the original message body or formatted userdata
exceeds the MAX_PRINT_CHUNK, append userdata to the netconsole message
starting with the first chunk that has available space after writing the
body.

Co-developed-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Matthew Wood <thepacketgeek@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: netconsole: append userdata to netconsole messages

Append userdata to outgoing unfragmented (<1000 bytes) netconsole messages.
When sending messages the userdata string is already formatted and stored
in netconsole_target->userdata_complete.

Always write the outgoing message to buf, so userdata can be appended in
a standard fashion. This is a change from only using buf when the
release needs to be prepended to the message.

Co-developed-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Matthew Wood <thepacketgeek@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: netconsole: cache userdata formatted string in netconsole_target

Store a formatted string for userdata that will be appended to netconsole
messages. The string has a capacity of 4KB, as calculated by the userdatum
entry length of 256 bytes and a max of 16 userdata entries.

Update the stored netconsole_target->userdata_complete string with the new
formatted userdata values when a userdatum is created, edited, or
removed. Each userdata entry contains a trailing newline, which will be
formatted as such in netconsole messages::

6.7.0-rc8-virtme,12,500,1646292204,-;test
release=foo
something=bar
6.7.0-rc8-virtme,12,500,1646292204,-;another test
release=foo
something=bar

Enforcement of MAX_USERDATA_ITEMS is done in userdatum_make_item;
update_userdata will not check for this case but will skip any userdata
children over the limit of MAX_USERDATA_ITEMs.

If a userdata entry/dir is created but no value is provided, that entry
will be skipped. This is in part because update_userdata() can't be
called in userdatum_make_item() since the item will not have been added
to the userdata config_group children yet. To preserve the experience of
adding an empty userdata that doesn't show up in the netconsole
messages, purposefully skip empty userdata items even when
update_userdata() can be called.

Co-developed-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Matthew Wood <thepacketgeek@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: netconsole: add a userdata config_group member to netconsole_target

Create configfs machinery for netconsole userdata appending, which depends
on CONFIG_NETCONSOLE_DYNAMIC (for configfs interface). Add a userdata
config_group to netconsole_target for managing userdata entries as a tree
under the netconsole configfs subsystem. Directory names created under the
userdata directory become userdatum keys; the userdatum value is the
content of the value file.

Include the minimum-viable-changes for userdata configfs config_group.
init_target_config_group() ties in the complete configfs machinery to
avoid unused func/variable errors during build. Initializing the
netconsole_target->group is moved to init_target_config_group, which
will also init and add the userdata config_group.

Each userdatum entry has a limit of 256 bytes (54 for
the key/directory, 200 for the value, and 2 for '=' and '\n'
characters), which is enforced by the configfs functions for updating
the userdata config_group.

When a new netconsole_target is created, initialize the userdata
config_group and add it as a default group for netconsole_target
config_group, allowing the userdata configfs sub-tree to be presented
in the netconsole configfs tree under the userdata directory.

Co-developed-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Matthew Wood <thepacketgeek@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: netconsole: move newline trimming to function

Move newline trimming logic from `dev_name_store()` to a new function
(trim_newline()) for shared use in netconsole.c

Signed-off-by: Matthew Wood <thepacketgeek@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: netconsole: move netconsole_target config_item to config_group

In order to support a nested userdata config_group in later patches,
use a config_group for netconsole_target instead of a
config_item. It's a no-op functionality-wise, since
config_group maintains all features of a config_item via the cg_item
member.

Signed-off-by: Matthew Wood <thepacketgeek@gmail.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: netconsole: cleanup formatting lints

Address checkpatch lint suggestions in preparation for later changes

Signed-off-by: Matthew Wood <thepacketgeek@gmail.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

netconsole: Attach cmdline target to dynamic target

Enable the attachment of a dynamic target to the target created during
boot time. The boot-time targets are named as "cmdline\d", where "\d" is
a number starting at 0.

If the user creates a dynamic target named "cmdline0", it will attach to
the first target created at boot time (as defined in the
`netconsole=...` command line argument). `cmdline1` will attach to the
second target and so forth.

If there is no netconsole target created at boot time, then, the target
name could be reused.

Relevant design discussion:
https://lore.kernel.org/all/ZRWRal5bW93px4km@gmail.com/

Suggested-by: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20231012111401.333798-4-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

netconsole: Initialize configfs_item for default targets

For netconsole targets allocated during the boot time (passing
netconsole=... argument), netconsole_target->item is not initialized.
That is not a problem because it is not used inside configfs.

An upcoming patch will be using it, thus, initialize the targets with
the name 'cmdline' plus a counter starting from 0. This name will match
entries in the configfs later.

Suggested-by: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20231012111401.333798-3-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

netconsole: move init/cleanup functions lower

Move alloc_param_target() and its counterpart (free_param_target())
to the bottom of the file. These functions are called mostly at
initialization/cleanup of the module, and they should be just above the
callers, at the bottom of the file.

From a practical perspective, having alloc_param_target() at the bottom
of the file will avoid forward declaration later (in the following
patch).

Nothing changed other than the functions location.

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20231012111401.333798-2-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

netconsole: Enable compile time configuration

Enable netconsole features to be set at compilation time. Create two
Kconfig options that allow users to set extended logs and release
prepending features at compilation time.

Right now, the user needs to pass command line parameters to netconsole,
such as "+"/"r" to enable extended logs and version prepending features.

With these two options, the user could set the default values for the
features at compile time, and don't need to pass it in the command line
to get them enabled, simplifying the command line.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20230811093158.1678322-3-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

netconsole: Create a allocation helper

De-duplicate the initialization and allocation code for struct
netconsole_target.

The same allocation and initialization code is duplicated in two
different places in the netconsole subsystem, when the netconsole target
is initialized by command line parameters (alloc_param_target()), and
dynamically by sysfs (make_netconsole_target()).

Create a helper function, and call it from the two different functions.

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20230811093158.1678322-2-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

netconsole: Use kstrtobool() instead of kstrtoint()

Replace kstrtoint() by kstrtobool() in the sysfs _store() functions.
This improves the user usability and simplify the code.

With this fix, it is now possible to use [YyNn] to set and unset a
feature. Old behaviour is still unchanged.

kstrtobool() is also safer and doesn't need the extra validation that
is required when converting a string to bool (end field in the struct),
which makes the code simpler.

Suggested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20230721092146.4036622-2-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

netconsole: Use sysfs_emit() instead of snprintf()

According to the sysfs.rst documentation, _show() functions should only
use sysfs_emit() instead of snprintf().

Since snprintf() shouldn't be used in the sysfs _show() path, replace it
by sysfs_emit().

Suggested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20230721092146.4036622-1-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

netconsole: Append kernel version to message

Create a new netconsole runtime option that prepends the kernel version in
the netconsole message. This is useful to map kernel messages to kernel
version in a simple way, i.e., without checking somewhere which kernel
version the host that sent the message is using.

If this option is selected, then the "<release>," is prepended before the
netconsole message. This is an example of a netconsole output, with
release feature enabled:

6.4.0-01762-ga1ba2ffe946e;12,426,112883998,-;this is a test

Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20230714111330.3069605-1-leitao@debian.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

netconsole: avoid CON_ENABLED misuse to track registration

The CON_ENABLED flag is being misused to track whether or not the
extended console should be or has been registered. Instead use
a local variable to decide if the extended console should be
registered and console_is_registered() to determine if it has
been registered.

Also add a check in cleanup_netconsole() to only unregister the
extended console if it has been registered.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-32-john.ogness@linutronix.de

net: move from strlcpy with unused retval to strscpy

Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> # for CAN
Link: https://lore.kernel.org/r/20220830201457.7984-1-wsa+renesas@sang-engineering.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: rename reference+tracking helpers

Netdev reference helpers have a dev_ prefix for historic
reasons. Renaming the old helpers would be too much churn
but we can rename the tracking ones which are relatively
recent and should be the default for new code.

Rename:
dev_hold_track() -> netdev_hold()
dev_put_track() -> netdev_put()
dev_replace_track() -> netdev_ref_replace()

Link: https://lore.kernel.org/r/20220608043955.919359-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

netpoll: add net device refcount tracker to struct netpoll

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: netconsole: Add description for 'netconsole_target's extended attribute

Fixes the following W=1 kernel build warning(s):

drivers/net/netconsole.c:104: warning: Function parameter or member 'extended' not described in 'netconsole_target'

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201102114512.1062724-29-lee.jones@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 153

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 or at your option any
later version this program is distributed in the hope that it will
be useful but without any warranty without even the implied warranty
of merchantability or fitness for a particular purpose see the gnu
general public license for more details you should have received a
copy of the gnu general public license along with this program if
not write to the free software foundation inc 675 mass ave cambridge
ma 02139 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 77 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.837555891@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

netconsole: make config_item_type const

Make these structures const as they are either passed to the functions
having the argument as const or stored as a reference in the "ci_type"
const field of a config_item structure.

Done using Coccienlle.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

netconsole: Remove duplicate "netconsole: " logging prefix

It's already added by pr_fmt so remove the explicit use.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netconsole: use per-attribute show and store methods

Note that the old code actually used the store_attributes method to do
locking, this is moved into the individual methods.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

netconsole: implement extended console support

printk logbuf keeps various metadata and optional key=value dictionary for
structured messages, both of which are stripped when messages are handed
to regular console drivers.

It can be useful to have this metadata and dictionary available to
netconsole consumers. This obviously makes logging via netconsole more
complete and the sequence number in particular is useful in environments
where messages may be lost or reordered in transit - e.g. when netconsole
is used to collect messages in a large cluster where packets may have to
travel congested hops to reach the aggregator. The lost and reordered
messages can easily be identified and handled accordingly using the
sequence numbers.

printk recently added extended console support which can be selected by
setting CON_EXTENDED flag. From console driver side, not much changes.
The only difference is that the text passed to the write callback is
formatted the same way as /dev/kmsg.

This patch implements extended console support for netconsole which can be
enabled by either prepending "+" to a netconsole boot param entry or
echoing 1 to "extended" file in configfs. When enabled, netconsole
transmits extended log messages with headers identical to /dev/kmsg
output.

There's one complication due to message fragments. netconsole limits the
maximum message size to 1k and messages longer than that are split into
multiple fragments. As all extended console messages should carry
matching headers and be uniquely identifiable, each extended message
fragment carries full copy of the metadata and an extra header field to
identify the specific fragment. The optional header is of the form
"ncfrag=OFF/LEN" where OFF is the byte offset into the message body and
LEN is the total length.

To avoid unnecessarily making printk format extended messages, Extended
netconsole is registered with printk when the first extended netconsole is
configured.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David Miller <davem@davemloft.net>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

netconsole: make all dynamic netconsoles share a mutex

Currently, each dynamic netconsole_target uses its own separate mutex to
synchronize the configuration operations.

This patch replaces the per-netconsole_target mutexes with a single
mutex - dynamic_netconsole_mutex. The reduced granularity doesn't hurt
anything, the code is minutely simpler and this'd allow adding
operations which should be synchronized across all dynamic netconsoles.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David Miller <davem@davemloft.net>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

netconsole: make netconsole_target->enabled a bool

netconsole uses both bool and int for boolean values. Let's convert
nt->enabled to bool for consistency.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David Miller <davem@davemloft.net>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

netconsole: remove unnecessary netconsole_target_get/out() from write_msg()

write_msg() grabs target_list_lock and walks target_list invoking
netpool_send_udp() on each target. Curiously, it protects each iteration
with netconsole_target_get/put() even though it never releases
target_list_lock which protects all the members.

While this doesn't harm anything, it doesn't serve any purpose either.
The items on the list can't go away while target_list_lock is held.
Remove the unnecessary get/put pair.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David Miller <davem@davemloft.net>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

netconsole: Use eth_<foo>_addr instead of memset

Use the built-in function instead of memset.

Miscellanea:

Add #include <linux/etherdevice.h>

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netconsole: Convert to pr_<level>

Use a more current logging style.

Convert printks to pr_<level>.

Consolidate multiple printks into a single printk to avoid
any possible dmesg interleaving. Add a default "event" msg
in case the listed types are ever expanded.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netconsole: fix multiple race conditions

In every netconsole option that can be set through configfs there's a
race when checking for nt->enabled since it can be modified at the same
time. Probably the most damage can be done by store_enabled when racing
with another instance of itself. Fix all the races with one stone by
moving the mutex lock around the ->store call for all options.

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netconsole: fix NULL pointer dereference

We need to disable the netconsole (enabled = 0) before setting nt->np.dev
to NULL because otherwise we might still have users after the
netpoll_cleanup() since nt->enabled is set afterwards and we can
have a message which will result in a NULL pointer dereference.
It is very easy to hit dereferences all over the netpoll_send_udp function
by running the following two loops in parallel:
while [ 1 ]; do echo 1 > enabled; echo 0 > enabled; done;
while [ 1 ]; do echo 00:11:22:33:44:55 > remote_mac; done;
(the second loop is to generate messages, it can be done by anything)

We're safe to set nt->np.dev = NULL and nt->enabled = 0 with the spinlock
since it's required in the write_msg() function.

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Reviewed-by: Veacelsav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netconsole: fix a deadlock with rtnl and netconsole's mutex

This bug was introduced by commit
7a163bfb7ce50895bbe67300ea610d31b9c09230 ("netconsole: avoid a crash with
multiple sysfs writers"). In store_enabled() we have the following
sequence: acquire nt->mutex then rtnl, but in the netconsole netdev
notifier we have rtnl then nt->mutex effectively leading to a deadlock.
The NULL pointer dereference that the above commit tries to fix is
actually due to another bug in netpoll_cleanup(). This is fixed by dropping
the mutex from the netdev notifier as it's already protected by rtnl.

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netconsole: avoid a crash with multiple sysfs writers

When my 'ifup eth' script was fired multiple times and ran concurrent on
my laptop, for some obscure /etc scripting reason, it was revealed
that the store_enabled() function in netconsole doesn't handle it nicely,
as recorded by the Oops below (a syslog paste, but not mangled too much
to prevent from discerning the traceback).

On Linux 3.10.4, this patch seeks to remedy the problem, and it has been
running stable on my laptop for a few days.

[52608.609325] BUG: unable to handle kernel NULL pointer dereference at 00000000000003e0
[52608.609331] IP: [<ffffffff81532a17>] __netpoll_cleanup+0x27/0xe0
[52608.609339] PGD 15e51a067 PUD 15433e067 PMD 0
[52608.609343] Oops: 0000 [#1] SMP re firewire_ohci firewire_core crc_itu_t [last unloaded: kvm_intel]
[52608.609347] Modules linked in: kvm_intel tun vfat fat ppdev parport_pc parport fuse ipt_MASQUERADE usb_storage nf_conntrack_netbios_ns nf_conn [..garbled..]
[52608.609433] RAX: 0000000000000000 RBX: ffff880210bbcc68 RCX: 0000000000000000
[52608.609435] RDX: 0000000000000000 RSI: ffff8801ba447da0 RDI: ffff880210bbcc68
[52608.609437] RBP: ffff8801ba447e18 R08: 0000000000000000 R09: 0000000000000001
[52608.609439] R10: 000000000000000a R11: f000000000000000 R12: ffff880210bbcc68
[52608.609441] R13: ffff88020bc41000 R14: 0000000000000002 R15: 000000000000000200000000000
[52608.609443] FS: 00007f38d7bff740(0000) GS:ffff88021dc40000(0000) knlGS:0000000000000000
[52608.609446] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003300000000001427e0
[52608.609448] CR2: 00000000000003e0 CR3: 0000000154103000 CR4: 00000000001427e0
[52608.609450] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[52608.609452] netpoll: netconsole: local port 6665ess 10.0.0.27
[52608.609454] netpoll: netconsole: local IPv4 address 10.0.0.27
[52608.609456] netpoll: netconsole: interface 'em1'
[52608.609457] netpoll: netconsole: remote port 514ress 10.0.0.15
[52608.609459] netpoll: netconsole: remote IPv4 address 10.0.0.15:65:a8:9a:c7
[52608.609461] netpoll: netconsole: remote ethernet address 1c:6f:65:a8:9a:c7
[52608.609463] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[52608.609464] Stack:801ba447e08 ffff880210bbcc68 ffffffffffffffea ffff88020bc41000
[52608.609466] ffff8801ba447e08 ffff880210bbcc68 ffffffffffffffea ffff88020bc41000
[52608.609471] 0000000000000002 0000000000000002 ffff8801ba447e38 ffffffff81532af4
[52608.609475] 0000000000000000 ffff880210bbcc00 ffff8801ba447e78 ffffffff81420e7c
[52608.609479] Call Trace:
[52608.609484] [<ffffffff81532af4>] netpoll_cleanup+0x24/0x50
[52608.609489] [<ffffffff81420e7c>] store_enabled+0x5c/0xe0
[52608.609492] [<ffffffff81420abe>] netconsole_target_attr_store+0x2e/0x40
[52608.609498] [<ffffffff811ff2a2>] configfs_write_file+0xd2/0x130
[52608.609503] [<ffffffff81188f95>] vfs_write+0xc5/0x1f0
[52608.609506] [<ffffffff81189482>] SyS_write+0x52/0xa0/0x10
[52608.609511] [<ffffffff81628c2e>] ? do_page_fault+0xe/0x10
[52608.609516] [<ffffffff8162d402>] system_call_fastpath+0x16/0x1b
[52608.609517] Code: 1f 44 00 00 0f 1f 44 00 00 55 48 89 e5 48 83 ec 30 4c 89 65 e0 48 89 5d d8 49 89 fc 4c 89 6d e8 4c 89 75 f0 4c 89 7d f8 48 8 [..garbled..]
[52608.609559] RIP [<ffffffff81532a17>] __netpoll_cleanup+0x27/0xe0
[52608.609563] RSP <ffff8801ba447de8>
[52608.609564] CR2: 00000000000003e0
[52608.609567] ---[ end trace d25ec343349b61d2 ]---

Signed-off-by: Dan Aloni <alonid@postram.com>
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: David S. Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: core: move mac_pton() to lib/net_utils.c

Since we have at least one user of this function outside of CONFIG_NET
scope, we have to provide this function independently. The proposed
solution is to move it under lib/net_utils.c with corresponding
configuration variable and select wherever it is needed.

Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net: pass info struct via netdevice notifier

So far, only net_device * could be passed along with netdevice notifier
event. This patch provides a possibility to pass custom structure
able to provide info that event listener needs to know.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>

v2->v3: fix typo on simeth
shortened dev_getter
shortened notifier_info struct name
v1->v2: fix notifier_call parameter in call_netdevice_notifier()
Signed-off-by: David S. Miller <davem@davemloft.net>

netconsole: don't call __netpoll_cleanup() while atomic

__netpoll_cleanup() is called in netconsole_netdev_event() while holding a
spinlock. Release/acquire the spinlock before/after it and restart the
loop. Also, disable the netconsole completely, because we won't have chance
after the restart of the loop, and might end up in a situation where
nt->enabled == 1 and nt->np.dev == NULL.

Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netpoll: add IPv6 support

Currently, netpoll only supports IPv4. This patch adds IPv6
support to netpoll so that we can run netconsole over IPv6 network.

Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netpoll: prepare for ipv6

This patch adjusts some struct and functions, to prepare
for supporting IPv6.

Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netconsole: add oops_only module option

Some people wants to log only oops messages via netconsole,
(this is also why netoops was invented)
so add a module option for netconsole. This can be tuned
via /sys/module/netconsole/parameters/oops_only at run time
as well.

Cc: David Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netconsole: remove a redundant netconsole_target_put()

This netconsole_target_put() is obviously redundant, and it
causes a kernel segfault when removing a bridge device which has
netconsole running on it.

This is caused by:

commit 8d8fc29d02a33e4bd5f4fa47823c1fd386346093
Author: Amerigo Wang <amwang@redhat.com>
Date: Thu May 19 21:39:10 2011 +0000

netpoll: disable netpoll when enslave a device

Cc: David Miller <davem@davemloft.net>
(for all 3.x stable releases)
Cc: stable@vger.kernel.org
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netconsole: do not release spin_lock when calling __netpoll_cleanup

With the previous patch applied, __netpoll_cleanup() is non-block now,
so we don't need to release the spin_lock before calling it.

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net: Remove unnecessary k.alloc/v.alloc OOM messages

alloc failures use dump_stack so emitting an additional
out-of-memory message is an unnecessary duplication.

Remove the allocation failure messages.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netconsole: enable netconsole can make net_device refcnt incorrent

There is no check if netconsole is enabled current.
so when exec echo 1 > enabled;
the reference of net_device will increment always.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Acked-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netconsole: switch init_netconsole() to late_initcall

Commit 88491d8(drivers/net: Kconfig & Makefile cleanup) causes a
regression that netconsole does not work if netconsole and network
device driver are build into kernel, because netconsole is linked
before network device driver.

Andrew Morton suggested to fix this with initcall ordering.
Fixes it by switching init_netconsole() to late_initcall.

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rename NETDEV_BONDING_DESLAVE to NETDEV_RELEASE

s/NETDEV_BONDING_DESLAVE/NETDEV_RELEASE/ as Andy suggested.

Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Cc: Neil Horman <nhorman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netpoll: disable netpoll when enslave a device

V3: rename NETDEV_ENSLAVE to NETDEV_JOIN

Currently we do nothing when we enslave a net device which is running netconsole.
Neil pointed out that we may get weird results in such case, so let's disable
netpoll on the device being enslaved. I think it is too harsh to prevent
the device being ensalved if it is running netconsole.

By the way, this patch also removes the NETDEV_GOING_DOWN from netconsole
netdev notifier, because netpoll will check if the device is running or not
and we don't handle NETDEV_PRE_UP neither.

This patch is based on net-next-2.6.

Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: Neil Horman <nhorman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: add mac_pton() for parsing MAC address

mac_pton() parses MAC address in form XX:XX:XX:XX:XX:XX and only in that form.

mac_pton() doesn't dirty result until it's sure string representation is valid.

mac_pton() doesn't care about characters _after_ last octet,
it's up to caller to deal with it.

mac_pton() diverges from 0/-E return value convention.
Target usage:

if (!mac_pton(str, whatever->mac))
return -EINVAL;
/* ->mac being u8 [ETH_ALEN] is filled at this point. */
/* optionally check str[3 * ETH_ALEN - 1] for termination */

Use mac_pton() in pktgen and netconsole for start.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netconsole: switch to kstrto*() functions

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netconsole: fix deadlock when removing net driver that netconsole is using (v2)

A deadlock was reported to me recently that occured when netconsole was being
used in a virtual guest. If the virtio_net driver was removed while netconsole
was setup to use an interface that was driven by that driver, the guest
deadlocked. No backtrace was provided because netconsole was the only console
configured, but it became clear pretty quickly what the problem was. In
netconsole_netdev_event, if we get an unregister event, we call
__netpoll_cleanup with the target_list_lock held and irqs disabled.
__netpoll_cleanup can, if pending netpoll packets are waiting call
cancel_delayed_work_sync, which is a sleeping path. the might_sleep call in
that path gets triggered, causing a console warning to be issued. The
netconsole write handler of course tries to take the target_list_lock again,
which we already hold, causing deadlock.

The fix is pretty striaghtforward. Simply drop the target_list_lock and
re-enable irqs prior to calling __netpoll_cleanup, the re-acquire the lock, and
restart the loop. Confirmed by myself to fix the problem reported.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

netconsole: clarify stopping message

Signed-off-by: Ferenc Wagner <wferi@niif.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>

netconsole: don't announce stopping if nothing happened

Signed-off-by: Ferenc Wagner <wferi@niif.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>

bonding: Fix netconsole to not deadlock on rmmod

Netconsole calls netpoll_cleanup on receipt of a NETDEVICE_UNREGISTER event.
The notifier subsystem calls these event handlers with rtnl_lock held, which
netpoll_cleanup also takes, resulting in deadlock. Fix this by calling the
__netpoll_cleanup interior function instead, and fixing up the additional
pointers.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netpoll: add generic support for bridge and bonding devices

This whole patchset is for adding netpoll support to bridge and bonding
devices. I already tested it for bridge, bonding, bridge over bonding,
and bonding over bridge. It looks fine now.

To make bridge and bonding support netpoll, we need to adjust
some netpoll generic code. This patch does the following things:

1) introduce two new priv_flags for struct net_device:
IFF_IN_NETPOLL which identifies we are processing a netpoll;
IFF_DISABLE_NETPOLL is used to disable netpoll support for a device
at run-time;

2) introduce one new method for netdev_ops:
->ndo_netpoll_cleanup() is used to clean up netpoll when a device is
removed.

3) introduce netpoll_poll_dev() which takes a struct net_device * parameter;
export netpoll_send_skb() and netpoll_poll_dev() which will be used later;

4) hide a pointer to struct netpoll in struct netpoll_info, ditto.

5) introduce ->real_dev for struct netpoll.

6) introduce a new status NETDEV_BONDING_DESLAE, which is used to disable
netconsole before releasing a slave, to avoid deadlocks.

Cc: David Miller <davem@davemloft.net>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: WANG Cong <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

netconsole: take care of NETDEV_UNREGISTER event

When netconsole is loaded and a network interface fades away (e.g. on
rmmod $interface_driver_module) the rmmod remains stuck and some locks
are taken that prevent any additional module loading/unloading as well
as interface up/down changes.
In addition kernel logs (and console) get flooded at 10s interval with

[ 122.464065] unregister_netdevice: waiting for eth0 to become free. Usage count = 1
[ 132.704059] unregister_netdevice: waiting for eth0 to become free. Usage count = 1

This patch lets netconsole take NETDEV_UNREGISTER event into account
and release the affected interface if it was in use.

Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netpoll: store local and remote ip in net-endian

Allows for the removal of byteswapping in some places and
the removal of HIPQUAD (replaced by %pI4).

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: convert print_mac to %pM

This converts pretty much everything to print_mac. There were
a few things that had conflicts which I have just dropped for
now, no harm done.

I've built an allyesconfig with this and looked at the files
that weren't built very carefully, but it's a huge patch.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove newline from the description of module parameters

Some module parameters with only one line have the '\n' at the end of the
description. This is not needed nor wanted as after the description the
type (i.e. int) is followed by a newline.

Some modules contain a multi-line description, these are not affected
by this patch.

Signed-off-by: Niels de Vos <niels.devos@wincor-nixdorf.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: John W. Linville <linville@tuxdriver.com>
Cc: Ed L. Cashin <ecashin@coraid.com>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Roland Dreier <rolandd@cisco.com>
Acked-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

configfs: Allow ->make_item() and ->make_group() to return detailed errors.

The configfs operations ->make_item() and ->make_group() currently
return a new item/group. A return of NULL signifies an error. Because
of this, -ENOMEM is the only return code bubbled up the stack.

Multiple folks have requested the ability to return specific error codes
when these operations fail. This patch adds that ability by changing the
->make_item/group() ops to return ERR_PTR() values. These errors are
bubbled up appropriately. NULL returns are changed to -ENOMEM for
compatibility.

Also updated are the in-kernel users of configfs.

This is a rework of reverted commit 11c3b79218390a139f2d474ee1e983a672d5839a.

Signed-off-by: Joel Becker <joel.becker@oracle.com>

Revert "configfs: Allow ->make_item() and ->make_group() to return detailed errors."

This reverts commit 11c3b79218390a139f2d474ee1e983a672d5839a. The code
will move to PTR_ERR().

Signed-off-by: Joel Becker <joel.becker@oracle.com>

configfs: Allow ->make_item() and ->make_group() to return detailed errors.

The configfs operations ->make_item() and ->make_group() currently
return a new item/group. A return of NULL signifies an error. Because
of this, -ENOMEM is the only return code bubbled up the stack.

Multiple folks have requested the ability to return specific error codes
when these operations fail. This patch adds that ability by changing the
->make_item/group() ops to return an int.

Also updated are the in-kernel users of configfs.

Signed-off-by: Joel Becker <joel.becker@oracle.com>

netconsole: only set CON_PRINTBUFFER if the user specifies a netconsole

Since 0bcc1816188e570bde1d56a208996660f2633ae0 (netconsole: Support
dynamic reconfiguration using configfs), the netconsole is always
registered, regardless of whether the user actually specified a
netconsole configuration on the command line.

However because netconsole has CON_PRINTBUFFER set, when it is
registered it causes the printk buffer to be replayed to all consoles.
When there is no netconsole configured this is a) pointless, and b)
somewhat annoying for the user of the existing console.

So instead we should only set CON_PRINTBUFFER if there is a netconsole
configuration found on the command line. This retains the existing
behaviour if a netconsole is setup by the user, and avoids spamming
other consoles when we're only registering for the dynamic
netconsole case.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

netconsole: avoid null pointer dereference at show_local_mac()

This patch avoids a null pointer dereference when we read local_mac
for netconsole in configfs and shows default local mac address
value.

A null pointer dereference occurs when we call show_local_mac() via
local_mac entry in configfs before we setup the content of netpoll
using netpoll_setup().

Signed-off-by: Keiichi KII <k-keiichi@bx.jp.nec.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NETPOLL]: no need to store local_mac

The local_mac is managed by the network device, no need to keep a
spare copy and all the management problems that could cause.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET]: Introduce and use print_mac() and DECLARE_MAC_BUF()

This is nicer than the MAC_FMT stuff.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET] netconsole: Support dynamic reconfiguration using configfs

Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>.

This patch introduces support for dynamic reconfiguration (adding, removing
and/or modifying parameters of netconsole targets at runtime) using a
userspace interface exported via configfs. Documentation is also updated
accordingly.

Issues and brief design overview:

(1) Kernel-initiated creation / destruction of kernel objects is not
possible with configfs -- the lifetimes of the "config items" is managed
exclusively from userspace. But netconsole must support boot/module
params too, and these are parsed in kernel and hence netpolls must be
setup from the kernel. Joel Becker suggested to separately manage the
lifetimes of the two kinds of netconsole_target objects -- those created
via configfs mkdir(2) from userspace and those specified from the
boot/module option string. This adds complexity and some redundancy here
and also means that boot/module param-created targets are not exposed
through the configfs namespace (and hence cannot be updated / destroyed
dynamically). However, this saves us from locking / refcounting
complexities that would need to be introduced in configfs to support
kernel-initiated item creation / destroy there.

(2) In configfs, item creation takes place in the call chain of the
mkdir(2) syscall in the driver subsystem. If we used an ioctl(2) to
create / destroy objects from userspace, the special userspace program is
able to fill out the structure to be passed into the ioctl and hence
specify attributes such as local interface that are required at the time
we set up the netpoll. For configfs, this information is not available at
the time of mkdir(2). So, we keep all newly-created targets (via
configfs) disabled by default. The user is expected to set various
attributes appropriately (including the local network interface if
required) and then write(2) "1" to the "enabled" attribute. Thus,
netpoll_setup() is then called on the set parameters in the context of
_this_ write(2) on the "enabled" attribute itself. This design enables
the user to reconfigure existing netconsole targets at runtime to be
attached to newly-come-up interfaces that may not have existed when
netconsole was loaded or when the targets were actually created. All this
effectively enables us to get rid of custom ioctls.

(3) Ultra-paranoid configfs attribute show() and store() operations, with
sanity and input range checking, using only safe string primitives, and
compliant with the recommendations in Documentation/filesystems/sysfs.txt.

(4) A new function netpoll_print_options() is created in the netpoll API,
that just prints out the configured parameters for a netpoll structure.
netpoll_parse_options() is modified to use that and it is also exported to
be used from netconsole.

Signed-off-by: Satyam Sharma <satyam@infradead.org>
Acked-by: Keiichi Kii <k-keiichi@bx.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET] netconsole: Support multiple logging targets

Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>.

This patch introduces support for multiple targets, independent of
CONFIG_NETCONSOLE_DYNAMIC -- this is useful even in the default case and
(including the infrastructure introduced in previous patches) doesn't really
add too many bytes to module text. All the complexity (and size) comes with
the dynamic reconfigurability / userspace interface patch, and so it's
plausible users may want to keep this enabled but that disabled (say to avoid
a dependency on CONFIG_CONFIGFS_FS too).

Also update documentation to mention the use of ";" separator to specify
multiple logging targets in the boot/module option string.

Brief overview:

We maintain a target_list (and corresponding lock). Get rid of the static
"default_target" and introduce allocation and release functions for our
netconsole_target objects (but keeping sure to preserve previous behaviour
such as default values). During init_netconsole(), ";" is used as the
separator to identify multiple target specifications in the boot/module option
string. The target specifications are parsed and netpolls setup. During
exit, the target_list is torn down and all items released.

Signed-off-by: Satyam Sharma <satyam@infradead.org>
Signed-off-by: Keiichi Kii <k-keiichi@bx.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET] netconsole: Introduce netconsole_netdev_notifier

Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>.

To update fields of underlying netpoll structure at runtime on corresponding
NETDEV_CHANGEADDR or NETDEV_CHANGENAME notifications.

ioctl(SIOCSIFHWADDR or SIOCSIFNAME) could be used to change the hardware/MAC
address or name of the local interface that our netpoll is attached to.
Whenever this happens, netdev notifier chain is called out with the
NETDEV_CHANGEADDR or NETDEV_CHANGENAME event message. We respond to that and
update the local_mac or dev_name field of the struct netpoll. This makes
sense anyway, but is especially required for dynamic netconsole because the
netpoll structure's internal members become user visible files when either
sysfs or configfs are used. So this helps us to keep up with the MAC
address/name changes and keep values in struct netpoll uptodate.

[ Note that ioctl(SIOCSIFADDR) to change IP address of interface at
runtime is not handled (to update local_ip of netpoll) on purpose --
some setups may set the local_ip to a private address, not necessary
the actual IP address of the sender host, as presently allowed. ]

Signed-off-by: Satyam Sharma <satyam@infradead.org>
Signed-off-by: Keiichi Kii <k-keiichi@bx.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET] netconsole: Introduce netconsole_target

Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>.

Introduce a wrapper structure over netpoll to represent logging targets
configured in netconsole. This will get extended with other members in
further patches.

This is done independent of the (to-be-introduced) NETCONSOLE_DYNAMIC config
option so that we're able to drastically cut down on the #ifdef complexity of
final netconsole.c. Also, struct netconsole_target would be required for
multiple targets support also, and not just dynamic reconfigurability.

Signed-off-by: Satyam Sharma <satyam@infradead.org>
Signed-off-by: Keiichi Kii <k-keiichi@bx.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET] netconsole: Use netif_running() in write_msg()

Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>.

Avoid unnecessarily disabling interrupts and calling netpoll_send_udp() if the
corresponding local interface is not up.

Signed-off-by: Satyam Sharma <satyam@infradead.org>
Acked-by: Keiichi Kii <k-keiichi@bx.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET] netconsole: Simplify boot/module option setup logic

Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>.

Presently, boot/module parameters are set up quite differently for the case of
built-in netconsole (__setup() -> obsolete_checksetup() ->
netpoll_parse_options() -> strlen(config) == 0 in init_netconsole()) vs
modular netconsole (module_param_string() -> string copied to the config
variable -> strlen(config) != 0 init_netconsole() -> netpoll_parse_options()).

This patch makes both of them similar by doing exactly the equivalent of a
module_param_string() in option_setup() also -- just copying the param string
passed from the kernel command line into "config" variable. So,
strlen(config) != 0 in both cases, and netpoll_parse_options() is always
called from init_netconsole(), thus making the setup logic for both cases
similar.

Now, option_setup() is only ever called / used for the built-in case, so we
put it inside a #ifndef MODULE, otherwise gcc will complain about
option_setup() being "defined but not used". Also, the "configured" variable
is redundant with this patch and hence removed.

Signed-off-by: Satyam Sharma <satyam@infradead.org>
Signed-off-by: Keiichi Kii <k-keiichi@bx.jp.nec.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET] netconsole: Remove bogus check

Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>.

The (!np.dev) check in write_msg() is bogus (always false), because: np.dev is
set by netpoll_setup(), which is called by init_netconsole() before
register_console(), so write_msg() cannot be triggered unless netpoll_setup()
successfully set np.dev. Also np.dev cannot go away from under us, because
netpoll_setup() grabs us reference on it. So let's remove the bogus check.

Signed-off-by: Satyam Sharma <satyam@infradead.org>
Acked-by: Keiichi Kii <k-keiichi@bx.jp.nec.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET] netconsole: Cleanups, codingstyle, prettyfication

Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>.

(1) Remove unwanted headers.
(2) Mark __init and __exit as appropriate.
(3) Various trivial codingstyle and prettification stuff.

Signed-off-by: Satyam Sharma <satyam@infradead.org>
Signed-off-by: Keiichi Kii <k-keiichi@bx.jp.nec.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

netpoll queue cleanup

The beast had a long and not very happy history. At one
point, a friend (netdump) had asked that he open up a little.
Well, the friend was long gone now, and the beast had
this dangling piece hanging (netpoll_queue).

It wasn't hard to stitch the netpoll_queue back in
where it belonged and make everything tidy.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>

netpoll setup error handling

The beast was not always healthy. When it was sick,
it tended to be laconic and not tell anyone the real problem.
A few small changes had it telling the world about its
problems, if they really wanted to hear.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>

[NETCONSOLE]: Clean up initcall warning.

From: Matt Mackall <mpm@selenic.com>

netconsole is being wrong here. If it wasn't enabled there's no error.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET] netconsole: set .name in struct console

Set .name in netconsole's struct console to identify the
struct's owner.

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

[PATCH] Don't pass boot parameters to argv_init[]

The boot cmdline is parsed in parse_early_param() and
parse_args(,unknown_bootoption).

And __setup() is used in obsolete_checksetup().

start_kernel()
-> parse_args()
-> unknown_bootoption()
-> obsolete_checksetup()

If __setup()'s callback (->setup_func()) returns 1 in
obsolete_checksetup(), obsolete_checksetup() thinks a parameter was
handled.

If ->setup_func() returns 0, obsolete_checksetup() tries other
->setup_func(). If all ->setup_func() that matched a parameter returns 0,
a parameter is seted to argv_init[].

Then, when runing /sbin/init or init=app, argv_init[] is passed to the app.
If the app doesn't ignore those arguments, it will warning and exit.

This patch fixes a wrong usage of it, however fixes obvious one only.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!