Conflicts:
arch/arm/boot/dts/imx6sx-sdb.dts
net/sched/cls_bpf.c
Two simple sets of overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
In addition to the problem Jeff Layton reported, I looked at the code
and reproduced the same warning by subscribing and removing the genl
family with a socket still open. This is a fairly tricky race which
originates in the fact that generic netlink allows the family to go
away while sockets are still open - unlike regular netlink which has
a module refcount for every open socket so in general this cannot be
triggered.
Trying to resolve this issue by the obvious locking isn't possible as
it will result in deadlocks between unregistration and group unbind
notification (which incidentally lockdep doesn't find due to the home
grown locking in the netlink table.)
To really resolve this, introduce a "closing socket" reference counter
(for generic netlink only, as it's the only affected family) in the
core netlink code and use that in generic netlink to wait for all the
sockets that are being closed at the same time as a generic netlink
family is removed.
This fixes the race that when a socket is closed, it will should call
the unbind, but if the family is removed at the same time the unbind
will not find it, leading to the warning. The real problem though is
that in this case the unbind could actually find a new family that is
registered to have a multicast group with the same ID, and call its
mcast_unbind() leading to confusing.
Also remove the warning since it would still trigger, but is now no
longer a problem.
This also moves the code in af_netlink.c to before unreferencing the
module to avoid having the same problem in the normal non-genl case.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As rhashtable_lookup_compare_insert() can guarantee the process
of search and insertion is atomic, it's safe to eliminate the
nl_sk_hash_lock. After this, object insertion or removal will
be protected with per bucket lock on write side while object
lookup is guarded with rcu read lock on read side.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Cc: Thomas Graf <tgraf@suug.ch>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Defers the release of the socket reference using call_rcu() to
allow using an RCU read-side protected call to rhashtable_lookup()
This restores behaviour and performance gains as previously
introduced by e341694 ("netlink: Convert netlink_lookup() to use
RCU protected hash table") without the side effect of severely
delayed socket destruction.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Netlink families can exist in multiple namespaces, and for the most
part multicast subscriptions are per network namespace. Thus it only
makes sense to have bind/unbind notifications per network namespace.
To achieve this, pass the network namespace of a given client socket
to the bind/unbind functions.
Also do this in generic netlink, and there also make sure that any
bind for multicast groups that only exist in init_net is rejected.
This isn't really a problem if it is accepted since a client in a
different namespace will never receive any notifications from such
a group, but it can confuse the family if not rejected (it's also
possible to silently (without telling the family) accept it, but it
would also have to be ignored on unbind so families that take any
kind of action on bind/unbind won't do unnecessary work for invalid
clients like that.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Although RCU protection would be possible during diag dump, doing
so allows for concurrent table mutations which can render the
in-table offset between individual Netlink messages invalid and
thus cause legitimate sockets to be skipped in the dump.
Since the diag dump is relatively low volume and consistency is
more important than performance, the table mutex is held during
dump.
Reported-by: Andrey Wagin <avagin@gmail.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Fixes: e341694e3e ("netlink: Convert netlink_lookup() to use RCU protected hash table")
Signed-off-by: David S. Miller <davem@davemloft.net>
Heavy Netlink users such as Open vSwitch spend a considerable amount of
time in netlink_lookup() due to the read-lock on nl_table_lock. Use of
RCU relieves the lock contention.
Makes use of the new resizable hash table to avoid locking on the
lookup.
The hash table will grow if entries exceeds 75% of table size up to a
total table size of 64K. It will automatically shrink if usage falls
below 30%.
Also splits nl_table_lock into a separate mutex to protect hash table
mutations and allow synchronize_rcu() to sleep while waiting for readers
during expansion and shrinking.
Before:
9.16% kpktgend_0 [openvswitch] [k] masked_flow_lookup
6.42% kpktgend_0 [pktgen] [k] mod_cur_headers
6.26% kpktgend_0 [pktgen] [k] pktgen_thread_worker
6.23% kpktgend_0 [kernel.kallsyms] [k] memset
4.79% kpktgend_0 [kernel.kallsyms] [k] netlink_lookup
4.37% kpktgend_0 [kernel.kallsyms] [k] memcpy
3.60% kpktgend_0 [openvswitch] [k] ovs_flow_extract
2.69% kpktgend_0 [kernel.kallsyms] [k] jhash2
After:
15.26% kpktgend_0 [openvswitch] [k] masked_flow_lookup
8.12% kpktgend_0 [pktgen] [k] pktgen_thread_worker
7.92% kpktgend_0 [pktgen] [k] mod_cur_headers
5.11% kpktgend_0 [kernel.kallsyms] [k] memset
4.11% kpktgend_0 [openvswitch] [k] ovs_flow_extract
4.06% kpktgend_0 [kernel.kallsyms] [k] _raw_spin_lock
3.90% kpktgend_0 [kernel.kallsyms] [k] jhash2
[...]
0.67% kpktgend_0 [kernel.kallsyms] [k] netlink_lookup
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Reviewed-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Have the netlink per-protocol optional bind function return an int error code
rather than void to signal a failure.
This will enable netlink protocols to perform extra checks including
capabilities and permissions verifications when updating memberships in
multicast groups.
In netlink_bind() and netlink_setsockopt() the call to the per-protocol bind
function was moved above the multicast group update to prevent any access to
the multicast socket groups before checking with the per-protocol bind
function. This will enable the per-protocol bind function to be used to check
permissions which could be denied before making them available, and to avoid
the messy job of undoing the addition should the per-protocol bind function
fail.
The netfilter subsystem seems to be the only one currently using the
per-protocol bind function.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
One known problem with netlink is the fact that NLMSG_GOODSIZE is
really small on PAGE_SIZE==4096 architectures, and it is difficult
to know in advance what buffer size is used by the application.
This patch adds an automatic learning of the size.
First netlink message will still be limited to ~4K, but if user used
bigger buffers, then following messages will be able to use up to 16KB.
This speedups dump() operations by a large factor and should be safe
for legacy applications.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Thomas Graf <tgraf@suug.ch>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Following patch stores struct netlink_callback in netlink_sock
to avoid allocating and freeing it on every netlink dump msg.
Only one dump operation is allowed for a given socket at a time
therefore we can safely convert cb pointer to cb struct inside
netlink_sock.
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As we know, netlink sockets are private resource of
net namespace, they can communicate with each other
only when they in the same net namespace. this works
well until we try to add namespace support for other
subsystems which use netlink.
Don't like ipv4 and route table.., it is not suited to
make these subsytems belong to net namespace, Such as
audit and crypto subsystems,they are more suitable to
user namespace.
So we must have the ability to make the netlink sockets
in same user namespace can communicate with each other.
This patch adds a new function pointer "compare" for
netlink_table, we can decide if the netlink sockets can
communicate with each other through this netlink_table
self-defined compare function.
The behavior isn't changed if we don't provide the compare
function for netlink_table.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support for mmap'ed RX and TX ring setup and teardown based on the
af_packet.c code. The following patches will use this to add the real
mmap'ed receive and transmit functionality.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move a few declarations in a header.
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Gao feng <gaofeng@cn.fujitsu.com>
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
