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 featur

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>

show more ...

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 p

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>

show more ...

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

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>

show more ...

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

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>

show more ...

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
versio

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>

show more ...

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 va

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

show more ...

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

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>

show more ...

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 ar

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>

show more ...

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 'e

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>

show more ...

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 th

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>

show more ...

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

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>

show more ...

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 <dave

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>

show more ...

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: Christ

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>

show more ...

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

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>

show more ...

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: 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>

show more ...

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>

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>

show more ...

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 protec

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>

show more ...

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-o

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>

show more ...

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

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>

show more ...

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

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>

show more ...

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() sin

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>

show more ...

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 s

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>

show more ...

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

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>

show more ...

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 t

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>

show more ...