There is a circular locking dependency when configuring the
hardware ARP filters on association, occurring when flushing the mac80211
workqueue. This is what happens:
[ 92.026800] =======================================================
[ 92.030507] [ INFO: possible circular locking dependency detected ]
[ 92.030507] 2.6.34-04781-g2b2c009 #85
[ 92.030507] -------------------------------------------------------
[ 92.030507] modprobe/5225 is trying to acquire lock:
[ 92.030507] ((wiphy_name(local->hw.wiphy))){+.+.+.}, at: [<ffffffff8105b5c0>] flush_workq
ueue+0x0/0xb0
[ 92.030507]
[ 92.030507] but task is already holding lock:
[ 92.030507] (rtnl_mutex){+.+.+.}, at: [<ffffffff812b9ce2>] rtnl_lock+0x12/0x20
[ 92.030507]
[ 92.030507] which lock already depends on the new lock.
[ 92.030507]
[ 92.030507]
[ 92.030507] the existing dependency chain (in reverse order) is:
[ 92.030507]
[ 92.030507] -> #2 (rtnl_mutex){+.+.+.}:
[ 92.030507] [<ffffffff810761fb>] lock_acquire+0xdb/0x110
[ 92.030507] [<ffffffff81341754>] mutex_lock_nested+0x44/0x300
[ 92.030507] [<ffffffff812b9ce2>] rtnl_lock+0x12/0x20
[ 92.030507] [<ffffffffa022d47c>] ieee80211_assoc_done+0x6c/0xe0 [mac80211]
[ 92.030507] [<ffffffffa022f2ad>] ieee80211_work_work+0x31d/0x1280 [mac80211]
[ 92.030507] -> #1 ((&local->work_work)){+.+.+.}:
[ 92.030507] [<ffffffff810761fb>] lock_acquire+0xdb/0x110
[ 92.030507] [<ffffffff8105a51a>] worker_thread+0x22a/0x370
[ 92.030507] [<ffffffff8105ecc6>] kthread+0x96/0xb0
[ 92.030507] [<ffffffff81003a94>] kernel_thread_helper+0x4/0x10
[ 92.030507]
[ 92.030507] -> #0 ((wiphy_name(local->hw.wiphy))){+.+.+.}:
[ 92.030507] [<ffffffff81075fdc>] __lock_acquire+0x1c0c/0x1d50
[ 92.030507] [<ffffffff810761fb>] lock_acquire+0xdb/0x110
[ 92.030507] [<ffffffff8105b60e>] flush_workqueue+0x4e/0xb0
[ 92.030507] [<ffffffffa023ff7b>] ieee80211_stop_device+0x2b/0xb0 [mac80211]
[ 92.030507] [<ffffffffa0231635>] ieee80211_stop+0x3e5/0x680 [mac80211]
The locking in this case is quite complex. Fix the problem by rewriting the
way the hardware ARP filter list is handled - i.e. make a copy of the address
list to the bss_conf struct, and provide that list to the hardware driver
when needed.
The current patch will enable filtering also in promiscuous mode. This may need
to be changed in the future.
Reported-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This patch adds support to nl80211 and mac80211 to set basic rates when
joining/creating ibss network.
Original patch was posted by Johannes Berg on the linux-wireless posting list.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Teemu Paasikivi <ext-teemu.3.paasikivi@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Allow drivers to sleep, and indicate this in
the documentation. ath9k has some locking I
don't understand, so keep it safe and disable
BHs in it, all other drivers look fine with
the context change.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The non-irqsafe aggregation start/stop done
callbacks are currently only used by ath9k_htc,
and can cause callbacks into the driver again.
This might lead to locking issues, which will
only get worse as we modify locking. To avoid
trouble, remove the non-irqsafe versions and
change ath9k_htc to use those instead.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
gen_kill_estimator() API is incomplete or not well documented, since
caller should make sure an RCU grace period is respected before
freeing stats_lock.
This was partially addressed in commit 5d944c640b
(gen_estimator: deadlock fix), but same problem exist for all
gen_kill_estimator() users, if lock they use is not already RCU
protected.
A code review shows xt_RATEEST.c, act_api.c, act_police.c have this
problem. Other are ok because they use qdisc lock, already RCU
protected.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
remove useless union keyword in rtable, rt6_info and dn_route.
Since there is only one member in a union, the union keyword isn't useful.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 66018506e1 (ip: Router Alert RCU conversion) introduced RCU
lookups to ip_call_ra_chain(). It missed proper deinit phase :
When ip_ra_control() deletes an ip_ra_chain, it should make sure
ip_call_ra_chain() users can not start to use socket during the rcu
grace period. It should also delay the sock_put() after the grace
period, or we risk a premature socket freeing and corruptions, as
raw sockets are not rcu protected yet.
This delay avoids using expensive atomic_inc_not_zero() in
ip_call_ra_chain().
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
NOTRACK makes all cpus share a cache line on nf_conntrack_untracked
twice per packet, slowing down performance.
This patch converts it to a per_cpu variable.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
NOTRACK makes all cpus share a cache line on nf_conntrack_untracked
twice per packet. This is bad for performance.
__read_mostly annotation is also a bad choice.
This patch introduces IPS_UNTRACKED bit so that we can use later a
per_cpu untrack structure more easily.
A new helper, nf_ct_untracked_get() returns a pointer to
nf_conntrack_untracked.
Another one, nf_ct_untracked_status_or() is used by nf_nat_init() to add
IPS_NAT_DONE_MASK bits to untracked status.
nf_ct_is_untracked() prototype is changed to work on a nf_conn pointer.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Fix a whole bunch of kernel-doc warnings
and errors that crop up when running it on
mac80211 and cfg80211; the latter isn't
normally done so lots of bit-rot happened.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
We currently dirty two cache lines in struct xt_rateest, this hurts SMP
performance.
This patch moves lock/bstats/rstats at beginning of structure so that
they share a single cache line.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Straightforward conversion to RCU.
One rwlock becomes a spinlock, and is static.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch address a serious performance issue in reading the
TCP sockets table (/proc/net/tcp).
Reading the full table is done by a number of sequential read
operations. At each read operation, a seek is done to find the
last socket that was previously read. This seek operation requires
that the sockets in the table need to be counted up to the current
file position, and to count each of these requires taking a lock for
each non-empty bucket. The whole algorithm is O(n^2).
The fix is to cache the last bucket value, offset within the bucket,
and the file position returned by the last read operation. On the
next sequential read, the bucket and offset are used to find the
last read socket immediately without needing ot scan the previous
buckets the table. This algorithm t read the whole table is O(n).
The improvement offered by this patch is easily show by performing
cat'ing /proc/net/tcp on a machine with a lot of connections. With
about 182K connections in the table, I see the following:
- Without patch
time cat /proc/net/tcp > /dev/null
real 1m56.729s
user 0m0.214s
sys 1m56.344s
- With patch
time cat /proc/net/tcp > /dev/null
real 0m0.894s
user 0m0.290s
sys 0m0.594s
Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
xfrm triggers a warning if dst_pop() drops a refcount
on a noref dst. This patch changes dst_pop() to
skb_dst_pop(). skb_dst_pop() drops the refcnt only
on a refcounted dst. Also we don't clone the child
dst_entry, so it is not refcounted and we can use
skb_dst_set_noref() in xfrm_output_one().
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
STA_NOTIFY_ADD and STA_NOTIFY_REMOVE have no users anymore,
and station addition/removal are indicated to drivers
using sta_add() and sta_remove(), which can sleep.
Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
There's no sense in letting anything but internal
mac80211 functions set the initiator to anything
but WLAN_BACK_INITIATOR, since WLAN_BACK_RECIPIENT
is only valid when we have received a frame from
the peer, which we react to directly in mac80211.
The debugfs code I recently added got this wrong
as well.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Some hardware allow extended filtering of ARP frames not intended for
the host. To perform such filtering, the hardware needs to know the current
IP address(es) of the host, bound to its interface.
Add support for ARP filtering to mac80211 by adding a new op to the driver
interface, allowing to configure the current IP addresses. This op is called
upon association with the currently configured address(es), and when
associated whenever the IP address(es) change.
This patch adds configuration of IPv4 addresses only, as IPv6 addresses don't
need ARP filtering.
Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
There's a single use of this struct member, but
as it is write-only it clearly not necessary.
Thus we can free up some space here, even if we
don't need it right now it seems pointless to
carry around the variable.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
cleanup patch.
Use new __packed annotation in net/ and include/
(except netfilter)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When sending action frames, we want to verify
that we do that on the correct channel. However,
checking the channel type in addition can get in
the way, since the channel type could change on
the fly during an association, and it's not
useful to have the channel type anyway since it
has no effect on the transmission. Therefore,
make it optional to specify so that if wanted,
it can still be checked, but is not required.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Changli Gao
Patrick McHardy
Juuso Oikarinen
Teemu Paasikivi
Johannes Berg
Eric Dumazet
David S. Miller
Jiri Pirko
Johannes Berg
Tom Herbert
Steffen Klassert
Sujith