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>
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>
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 <davem@davemloft.net>
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>
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>
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>
This bug was introduced by commit
7a163bfb7c ("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>
Pull networking updates from David Miller:
"This is a re-do of the net-next pull request for the current merge
window. The only difference from the one I made the other day is that
this has Eliezer's interface renames and the timeout handling changes
made based upon your feedback, as well as a few bug fixes that have
trickeled in.
Highlights:
1) Low latency device polling, eliminating the cost of interrupt
handling and context switches. Allows direct polling of a network
device from socket operations, such as recvmsg() and poll().
Currently ixgbe, mlx4, and bnx2x support this feature.
Full high level description, performance numbers, and design in
commit 0a4db187a9 ("Merge branch 'll_poll'")
From Eliezer Tamir.
2) With the routing cache removed, ip_check_mc_rcu() gets exercised
more than ever before in the case where we have lots of multicast
addresses. Use a hash table instead of a simple linked list, from
Eric Dumazet.
3) Add driver for Atheros CQA98xx 802.11ac wireless devices, from
Bartosz Markowski, Janusz Dziedzic, Kalle Valo, Marek Kwaczynski,
Marek Puzyniak, Michal Kazior, and Sujith Manoharan.
4) Support reporting the TUN device persist flag to userspace, from
Pavel Emelyanov.
5) Allow controlling network device VF link state using netlink, from
Rony Efraim.
6) Support GRE tunneling in openvswitch, from Pravin B Shelar.
7) Adjust SOCK_MIN_RCVBUF and SOCK_MIN_SNDBUF for modern times, from
Daniel Borkmann and Eric Dumazet.
8) Allow controlling of TCP quickack behavior on a per-route basis,
from Cong Wang.
9) Several bug fixes and improvements to vxlan from Stephen
Hemminger, Pravin B Shelar, and Mike Rapoport. In particular,
support receiving on multiple UDP ports.
10) Major cleanups, particular in the area of debugging and cookie
lifetime handline, to the SCTP protocol code. From Daniel
Borkmann.
11) Allow packets to cross network namespaces when traversing tunnel
devices. From Nicolas Dichtel.
12) Allow monitoring netlink traffic via AF_PACKET sockets, in a
manner akin to how we monitor real network traffic via ptype_all.
From Daniel Borkmann.
13) Several bug fixes and improvements for the new alx device driver,
from Johannes Berg.
14) Fix scalability issues in the netem packet scheduler's time queue,
by using an rbtree. From Eric Dumazet.
15) Several bug fixes in TCP loss recovery handling, from Yuchung
Cheng.
16) Add support for GSO segmentation of MPLS packets, from Simon
Horman.
17) Make network notifiers have a real data type for the opaque
pointer that's passed into them. Use this to properly handle
network device flag changes in arp_netdev_event(). From Jiri
Pirko and Timo Teräs.
18) Convert several drivers over to module_pci_driver(), from Peter
Huewe.
19) tcp_fixup_rcvbuf() can loop 500 times over loopback, just use a
O(1) calculation instead. From Eric Dumazet.
20) Support setting of explicit tunnel peer addresses in ipv6, just
like ipv4. From Nicolas Dichtel.
21) Protect x86 BPF JIT against spraying attacks, from Eric Dumazet.
22) Prevent a single high rate flow from overruning an individual cpu
during RX packet processing via selective flow shedding. From
Willem de Bruijn.
23) Don't use spinlocks in TCP md5 signing fast paths, from Eric
Dumazet.
24) Don't just drop GSO packets which are above the TBF scheduler's
burst limit, chop them up so they are in-bounds instead. Also
from Eric Dumazet.
25) VLAN offloads are missed when configured on top of a bridge, fix
from Vlad Yasevich.
26) Support IPV6 in ping sockets. From Lorenzo Colitti.
27) Receive flow steering targets should be updated at poll() time
too, from David Majnemer.
28) Fix several corner case regressions in PMTU/redirect handling due
to the routing cache removal, from Timo Teräs.
29) We have to be mindful of ipv4 mapped ipv6 sockets in
upd_v6_push_pending_frames(). From Hannes Frederic Sowa.
30) Fix L2TP sequence number handling bugs, from James Chapman."
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1214 commits)
drivers/net: caif: fix wrong rtnl_is_locked() usage
drivers/net: enic: release rtnl_lock on error-path
vhost-net: fix use-after-free in vhost_net_flush
net: mv643xx_eth: do not use port number as platform device id
net: sctp: confirm route during forward progress
virtio_net: fix race in RX VQ processing
virtio: support unlocked queue poll
net/cadence/macb: fix bug/typo in extracting gem_irq_read_clear bit
Documentation: Fix references to defunct linux-net@vger.kernel.org
net/fs: change busy poll time accounting
net: rename low latency sockets functions to busy poll
bridge: fix some kernel warning in multicast timer
sfc: Fix memory leak when discarding scattered packets
sit: fix tunnel update via netlink
dt:net:stmmac: Add dt specific phy reset callback support.
dt:net:stmmac: Add support to dwmac version 3.610 and 3.710
dt:net:stmmac: Allocate platform data only if its NULL.
net:stmmac: fix memleak in the open method
ipv6: rt6_check_neigh should successfully verify neigh if no NUD information are available
net: ipv6: fix wrong ping_v6_sendmsg return value
...
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>
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>
__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>
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>
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>
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>
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 8d8fc29d02
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>
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>
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>
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>
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>
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>
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>
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>
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 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>
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>
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>
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>
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>
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>
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>
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 11c3b79218.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
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>
Since 0bcc181618 (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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
