linux-toradex.git/drivers/net/netconsole.c, branch v4.11-rc1

netconsole: use per-attribute show and store methods

2015-10-14T05:17:51+00:00

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 
Signed-off-by: Nicholas Bellinger

netconsole: implement extended console support

2015-06-26T00:00:39+00:00

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 
Cc: David Miller 
Cc: Kay Sievers 
Cc: Petr Mladek 
Cc: Tetsuo Handa 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

netconsole: make all dynamic netconsoles share a mutex

2015-06-26T00:00:39+00:00

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 
Cc: David Miller 
Cc: Kay Sievers 
Cc: Petr Mladek 
Cc: Tetsuo Handa 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

netconsole: make netconsole_target->enabled a bool

2015-06-26T00:00:39+00:00

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

Signed-off-by: Tejun Heo 
Cc: David Miller 
Cc: Kay Sievers 
Cc: Petr Mladek 
Cc: Tetsuo Handa 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

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

2015-06-26T00:00:39+00:00

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 
Cc: David Miller 
Cc: Kay Sievers 
Cc: Petr Mladek 
Cc: Tetsuo Handa 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

netconsole: Use eth__addr instead of memset

2015-03-03T22:01:37+00:00

Use the built-in function instead of memset.

Miscellanea:

Add #include 

Signed-off-by: Joe Perches 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2013-11-04T18:48:30+00:00

Conflicts:
	drivers/net/ethernet/emulex/benet/be.h
	drivers/net/netconsole.c
	net/bridge/br_private.h

Three mostly trivial conflicts.

The net/bridge/br_private.h conflict was a function signature (argument
addition) change overlapping with the extern removals from Joe Perches.

In drivers/net/netconsole.c we had one change adjusting a printk message
whilst another changed "printk(KERN_INFO" into "pr_info(".

Lastly, the emulex change was a new inline function addition overlapping
with Joe Perches's extern removals.

Signed-off-by: David S. Miller

netconsole: Convert to pr_

2013-10-29T21:41:49+00:00

Use a more current logging style.

Convert printks to pr_.

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 
Signed-off-by: David S. Miller

netconsole: fix multiple race conditions

2013-10-25T23:26:58+00:00

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 
Signed-off-by: David S. Miller

netconsole: fix NULL pointer dereference

2013-10-25T23:26:58+00:00

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 
Reviewed-by: Veacelsav Falico 
Signed-off-by: David S. Miller