Commit Graph

378663 Commits

Author SHA1 Message Date
Julian Anastasov
044d6efb79 ipv6: fill rt6i_gateway with nexthop address
[ Upstream commit 550bab42f8 ]

Make sure rt6i_gateway contains nexthop information in
all routes returned from lookup or when routes are directly
attached to skb for generated ICMP packets.

The effect of this patch should be a faster version of
rt6_nexthop() and the consideration of local addresses as
nexthop.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:05 -08:00
Julian Anastasov
208a6152b6 ipv6: always prefer rt6i_gateway if present
[ Upstream commit 96dc809514 ]

In v3.9 6fd6ce2056 ("ipv6: Do not depend on rt->n in
ip6_finish_output2()." changed the behaviour of ip6_finish_output2()
such that the recently introduced rt6_nexthop() is used
instead of an assigned neighbor.

As rt6_nexthop() prefers rt6i_gateway only for gatewayed
routes this causes a problem for users like IPVS, xt_TEE and
RAW(hdrincl) if they want to use different address for routing
compared to the destination address.

Another case is when redirect can create RTF_DYNAMIC
route without RTF_GATEWAY flag, we ignore the rt6i_gateway
in rt6_nexthop().

Fix the above problems by considering the rt6i_gateway if
present, so that traffic routed to address on local subnet is
not wrongly diverted to the destination address.

Thanks to Simon Horman and Phil Oester for spotting the
problematic commit.

Thanks to Hannes Frederic Sowa for his review and help in testing.

Reported-by: Phil Oester <kernel@linuxace.com>
Reported-by: Mark Brooks <mark@loadbalancer.org>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:05 -08:00
Hannes Frederic Sowa
b90cd7b9d0 inet: fix possible memory corruption with UDP_CORK and UFO
[ This is a simplified -stable version of a set of upstream commits. ]

This is a replacement patch only for stable which does fix the problems
handled by the following two commits in -net:

"ip_output: do skb ufo init for peeked non ufo skb as well" (e93b7d748b)
"ip6_output: do skb ufo init for peeked non ufo skb as well" (c547dbf55d)

Three frames are written on a corked udp socket for which the output
netdevice has UFO enabled.  If the first and third frame are smaller than
the mtu and the second one is bigger, we enqueue the second frame with
skb_append_datato_frags without initializing the gso fields. This leads
to the third frame appended regulary and thus constructing an invalid skb.

This fixes the problem by always using skb_append_datato_frags as soon
as the first frag got enqueued to the skb without marking the packet
as SKB_GSO_UDP.

The problem with only two frames for ipv6 was fixed by "ipv6: udp
packets following an UFO enqueued packet need also be handled by UFO"
(2811ebac25).

Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:05 -08:00
Seif Mazareeb
872095cb74 net: fix cipso packet validation when !NETLABEL
[ Upstream commit f2e5ddcc0d ]

When CONFIG_NETLABEL is disabled, the cipso_v4_validate() function could loop
forever in the main loop if opt[opt_iter +1] == 0, this will causing a kernel
crash in an SMP system, since the CPU executing this function will
stall /not respond to IPIs.

This problem can be reproduced by running the IP Stack Integrity Checker
(http://isic.sourceforge.net) using the following command on a Linux machine
connected to DUT:

"icmpsic -s rand -d <DUT IP address> -r 123456"
wait (1-2 min)

Signed-off-by: Seif Mazareeb <seif@marvell.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:04 -08:00
Daniel Borkmann
a769ad65ce net: unix: inherit SOCK_PASS{CRED, SEC} flags from socket to fix race
[ Upstream commit 90c6bd34f8 ]

In the case of credentials passing in unix stream sockets (dgram
sockets seem not affected), we get a rather sparse race after
commit 16e5726 ("af_unix: dont send SCM_CREDENTIALS by default").

We have a stream server on receiver side that requests credential
passing from senders (e.g. nc -U). Since we need to set SO_PASSCRED
on each spawned/accepted socket on server side to 1 first (as it's
not inherited), it can happen that in the time between accept() and
setsockopt() we get interrupted, the sender is being scheduled and
continues with passing data to our receiver. At that time SO_PASSCRED
is neither set on sender nor receiver side, hence in cmsg's
SCM_CREDENTIALS we get eventually pid:0, uid:65534, gid:65534
(== overflow{u,g}id) instead of what we actually would like to see.

On the sender side, here nc -U, the tests in maybe_add_creds()
invoked through unix_stream_sendmsg() would fail, as at that exact
time, as mentioned, the sender has neither SO_PASSCRED on his side
nor sees it on the server side, and we have a valid 'other' socket
in place. Thus, sender believes it would just look like a normal
connection, not needing/requesting SO_PASSCRED at that time.

As reverting 16e5726 would not be an option due to the significant
performance regression reported when having creds always passed,
one way/trade-off to prevent that would be to set SO_PASSCRED on
the listener socket and allow inheriting these flags to the spawned
socket on server side in accept(). It seems also logical to do so
if we'd tell the listener socket to pass those flags onwards, and
would fix the race.

Before, strace:

recvmsg(4, {msg_name(0)=NULL, msg_iov(1)=[{"blub\n", 4096}],
        msg_controllen=32, {cmsg_len=28, cmsg_level=SOL_SOCKET,
        cmsg_type=SCM_CREDENTIALS{pid=0, uid=65534, gid=65534}},
        msg_flags=0}, 0) = 5

After, strace:

recvmsg(4, {msg_name(0)=NULL, msg_iov(1)=[{"blub\n", 4096}],
        msg_controllen=32, {cmsg_len=28, cmsg_level=SOL_SOCKET,
        cmsg_type=SCM_CREDENTIALS{pid=11580, uid=1000, gid=1000}},
        msg_flags=0}, 0) = 5

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:04 -08:00
Vasundhara Volam
a8410b48a2 be2net: pass if_id for v1 and V2 versions of TX_CREATE cmd
[ Upstream commit 0fb88d61bc ]

It is a required field for all TX_CREATE cmd versions > 0.
This fixes a driver initialization failure, caused by recent SH-R Firmwares
(versions > 10.0.639.0) failing the TX_CREATE cmd when if_id field is
not passed.

Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:04 -08:00
Salva Peiró
8ffb77d881 wanxl: fix info leak in ioctl
[ Upstream commit 2b13d06c95 ]

The wanxl_ioctl() code fails to initialize the two padding bytes of
struct sync_serial_settings after the ->loopback member. Add an explicit
memset(0) before filling the structure to avoid the info leak.

Signed-off-by: Salva Peiró <speiro@ai2.upv.es>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:04 -08:00
Vlad Yasevich
c69ee66768 sctp: Perform software checksum if packet has to be fragmented.
[ Upstream commit d2dbbba77e ]

IP/IPv6 fragmentation knows how to compute only TCP/UDP checksum.
This causes problems if SCTP packets has to be fragmented and
ipsummed has been set to PARTIAL due to checksum offload support.
This condition can happen when retransmitting after MTU discover,
or when INIT or other control chunks are larger then MTU.
Check for the rare fragmentation condition in SCTP and use software
checksum calculation in this case.

CC: Fan Du <fan.du@windriver.com>
Signed-off-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:04 -08:00
Fan Du
935be1dc2c sctp: Use software crc32 checksum when xfrm transform will happen.
[ Upstream commit 27127a8256 ]

igb/ixgbe have hardware sctp checksum support, when this feature is enabled
and also IPsec is armed to protect sctp traffic, ugly things happened as
xfrm_output checks CHECKSUM_PARTIAL to do checksum operation(sum every thing
up and pack the 16bits result in the checksum field). The result is fail
establishment of sctp communication.

Signed-off-by: Fan Du <fan.du@windriver.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:04 -08:00
Vlad Yasevich
c9446ff691 net: dst: provide accessor function to dst->xfrm
[ Upstream commit e87b3998d7 ]

dst->xfrm is conditionally defined.  Provide accessor funtion that
is always available.

Signed-off-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:03 -08:00
Vlad Yasevich
d14db23276 bridge: Correctly clamp MAX forward_delay when enabling STP
[ Upstream commit 4b6c7879d8 ]

Commit be4f154d5e
	bridge: Clamp forward_delay when enabling STP
had a typo when attempting to clamp maximum forward delay.

It is possible to set bridge_forward_delay to be higher then
permitted maximum when STP is off.  When turning STP on, the
higher then allowed delay has to be clamed down to max value.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
CC: Herbert Xu <herbert@gondor.apana.org.au>
CC: Stephen Hemminger <shemminger@vyatta.com>
Reviewed-by: Veaceslav Falico <vfalico@redhat.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:03 -08:00
Jason Wang
30983d3c66 virtio-net: refill only when device is up during setting queues
[ Upstream commit 35ed159bfd ]

We used to schedule the refill work unconditionally after changing the
number of queues. This may lead an issue if the device is not
up. Since we only try to cancel the work in ndo_stop(), this may cause
the refill work still work after removing the device. Fix this by only
schedule the work when device is up.

The bug were introduce by commit 9b9cd8024a.
(virtio-net: fix the race between channels setting and refill)

Signed-off-by: Jason Wang <jasowang@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:03 -08:00
Jason Wang
413054e740 virtio-net: fix the race between channels setting and refill
[ Upstream commit 9b9cd8024a ]

Commit 55257d72bd (virtio-net: fill only rx queues
which are being used) tries to refill on demand when changing the number of
channels by call try_refill_recv() directly, this may race:

- the refill work who may do the refill in the same time
- the try_refill_recv() called in bh since napi was not disabled

Which may led guest complain during setting channels:

virtio_net virtio0: input.1:id 0 is not a head!

Solve this issue by scheduling a refill work which can guarantee the
serialization of refill.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:03 -08:00
Jason Wang
f02721718c virtio-net: don't respond to cpu hotplug notifier if we're not ready
[ Upstream commit 3ab098df35 ]

We're trying to re-configure the affinity unconditionally in cpu hotplug
callback. This may lead the issue during resuming from s3/s4 since

- virt queues haven't been allocated at that time.
- it's unnecessary since thaw method will re-configure the affinity.

Fix this issue by checking the config_enable and do nothing is we're not ready.

The bug were introduced by commit 8de4b2f3ae
(virtio-net: reset virtqueue affinity when doing cpu hotplug).

Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Reviewed-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:03 -08:00
Eric Dumazet
608be70366 bnx2x: record rx queue for LRO packets
[ Upstream commit 60e66fee56 ]

RPS support is kind of broken on bnx2x, because only non LRO packets
get proper rx queue information. This triggers reorders, as it seems
bnx2x like to generate a non LRO packet for segment including TCP PUSH
flag : (this might be pure coincidence, but all the reorders I've
seen involve segments with a PUSH)

11:13:34.335847 IP A > B: . 415808:447136(31328) ack 1 win 457 <nop,nop,timestamp 3789336 3985797>
11:13:34.335992 IP A > B: . 447136:448560(1424) ack 1 win 457 <nop,nop,timestamp 3789336 3985797>
11:13:34.336391 IP A > B: . 448560:479888(31328) ack 1 win 457 <nop,nop,timestamp 3789337 3985797>
11:13:34.336425 IP A > B: P 511216:512640(1424) ack 1 win 457 <nop,nop,timestamp 3789337 3985798>
11:13:34.336423 IP A > B: . 479888:511216(31328) ack 1 win 457 <nop,nop,timestamp 3789337 3985798>
11:13:34.336924 IP A > B: . 512640:543968(31328) ack 1 win 457 <nop,nop,timestamp 3789337 3985798>
11:13:34.336963 IP A > B: . 543968:575296(31328) ack 1 win 457 <nop,nop,timestamp 3789337 3985798>

We must call skb_record_rx_queue() to properly give to RPS (and more
generally for TX queue selection on forward path) the receive queue
information.

Similar fix is needed for skb_mark_napi_id(), but will be handled
in a separate patch to ease stable backports.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Eilon Greenstein <eilong@broadcom.com>
Acked-by: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:03 -08:00
Mathias Krause
69b9c5ea56 connector: use nlmsg_len() to check message length
[ Upstream commit 162b2bedc0 ]

The current code tests the length of the whole netlink message to be
at least as long to fit a cn_msg. This is wrong as nlmsg_len includes
the length of the netlink message header. Use nlmsg_len() instead to
fix this "off-by-NLMSG_HDRLEN" size check.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:02 -08:00
Mathias Krause
39283085a9 unix_diag: fix info leak
[ Upstream commit 6865d1e834 ]

When filling the netlink message we miss to wipe the pad field,
therefore leak one byte of heap memory to userland. Fix this by
setting pad to 0.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:02 -08:00
Salva Peiró
3a26736015 farsync: fix info leak in ioctl
[ Upstream commit 96b3404067 ]

The fst_get_iface() code fails to initialize the two padding bytes of
struct sync_serial_settings after the ->loopback member. Add an explicit
memset(0) before filling the structure to avoid the info leak.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:02 -08:00
Eric Dumazet
a41536775e l2tp: must disable bh before calling l2tp_xmit_skb()
[ Upstream commit 455cc32bf1 ]

François Cachereul made a very nice bug report and suspected
the bh_lock_sock() / bh_unlok_sock() pair used in l2tp_xmit_skb() from
process context was not good.

This problem was added by commit 6af88da14e
("l2tp: Fix locking in l2tp_core.c").

l2tp_eth_dev_xmit() runs from BH context, so we must disable BH
from other l2tp_xmit_skb() users.

[  452.060011] BUG: soft lockup - CPU#1 stuck for 23s! [accel-pppd:6662]
[  452.061757] Modules linked in: l2tp_ppp l2tp_netlink l2tp_core pppoe pppox
ppp_generic slhc ipv6 ext3 mbcache jbd virtio_balloon xfs exportfs dm_mod
virtio_blk ata_generic virtio_net floppy ata_piix libata virtio_pci virtio_ring virtio [last unloaded: scsi_wait_scan]
[  452.064012] CPU 1
[  452.080015] BUG: soft lockup - CPU#2 stuck for 23s! [accel-pppd:6643]
[  452.080015] CPU 2
[  452.080015]
[  452.080015] Pid: 6643, comm: accel-pppd Not tainted 3.2.46.mini #1 Bochs Bochs
[  452.080015] RIP: 0010:[<ffffffff81059f6c>]  [<ffffffff81059f6c>] do_raw_spin_lock+0x17/0x1f
[  452.080015] RSP: 0018:ffff88007125fc18  EFLAGS: 00000293
[  452.080015] RAX: 000000000000aba9 RBX: ffffffff811d0703 RCX: 0000000000000000
[  452.080015] RDX: 00000000000000ab RSI: ffff8800711f6896 RDI: ffff8800745c8110
[  452.080015] RBP: ffff88007125fc18 R08: 0000000000000020 R09: 0000000000000000
[  452.080015] R10: 0000000000000000 R11: 0000000000000280 R12: 0000000000000286
[  452.080015] R13: 0000000000000020 R14: 0000000000000240 R15: 0000000000000000
[  452.080015] FS:  00007fdc0cc24700(0000) GS:ffff8800b6f00000(0000) knlGS:0000000000000000
[  452.080015] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  452.080015] CR2: 00007fdb054899b8 CR3: 0000000074404000 CR4: 00000000000006a0
[  452.080015] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  452.080015] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  452.080015] Process accel-pppd (pid: 6643, threadinfo ffff88007125e000, task ffff8800b27e6dd0)
[  452.080015] Stack:
[  452.080015]  ffff88007125fc28 ffffffff81256559 ffff88007125fc98 ffffffffa01b2bd1
[  452.080015]  ffff88007125fc58 000000000000000c 00000000029490d0 0000009c71dbe25e
[  452.080015]  000000000000005c 000000080000000e 0000000000000000 ffff880071170600
[  452.080015] Call Trace:
[  452.080015]  [<ffffffff81256559>] _raw_spin_lock+0xe/0x10
[  452.080015]  [<ffffffffa01b2bd1>] l2tp_xmit_skb+0x189/0x4ac [l2tp_core]
[  452.080015]  [<ffffffffa01c2d36>] pppol2tp_sendmsg+0x15e/0x19c [l2tp_ppp]
[  452.080015]  [<ffffffff811c7872>] __sock_sendmsg_nosec+0x22/0x24
[  452.080015]  [<ffffffff811c83bd>] sock_sendmsg+0xa1/0xb6
[  452.080015]  [<ffffffff81254e88>] ? __schedule+0x5c1/0x616
[  452.080015]  [<ffffffff8103c7c6>] ? __dequeue_signal+0xb7/0x10c
[  452.080015]  [<ffffffff810bbd21>] ? fget_light+0x75/0x89
[  452.080015]  [<ffffffff811c8444>] ? sockfd_lookup_light+0x20/0x56
[  452.080015]  [<ffffffff811c9b34>] sys_sendto+0x10c/0x13b
[  452.080015]  [<ffffffff8125cac2>] system_call_fastpath+0x16/0x1b
[  452.080015] Code: 81 48 89 e5 72 0c 31 c0 48 81 ff 45 66 25 81 0f 92 c0 5d c3 55 b8 00 01 00 00 48 89 e5 f0 66 0f c1 07 0f b6 d4 38 d0 74 06 f3 90 <8a> 07 eb f6 5d c3 90 90 55 48 89 e5 9c 58 0f 1f 44 00 00 5d c3
[  452.080015] Call Trace:
[  452.080015]  [<ffffffff81256559>] _raw_spin_lock+0xe/0x10
[  452.080015]  [<ffffffffa01b2bd1>] l2tp_xmit_skb+0x189/0x4ac [l2tp_core]
[  452.080015]  [<ffffffffa01c2d36>] pppol2tp_sendmsg+0x15e/0x19c [l2tp_ppp]
[  452.080015]  [<ffffffff811c7872>] __sock_sendmsg_nosec+0x22/0x24
[  452.080015]  [<ffffffff811c83bd>] sock_sendmsg+0xa1/0xb6
[  452.080015]  [<ffffffff81254e88>] ? __schedule+0x5c1/0x616
[  452.080015]  [<ffffffff8103c7c6>] ? __dequeue_signal+0xb7/0x10c
[  452.080015]  [<ffffffff810bbd21>] ? fget_light+0x75/0x89
[  452.080015]  [<ffffffff811c8444>] ? sockfd_lookup_light+0x20/0x56
[  452.080015]  [<ffffffff811c9b34>] sys_sendto+0x10c/0x13b
[  452.080015]  [<ffffffff8125cac2>] system_call_fastpath+0x16/0x1b
[  452.064012]
[  452.064012] Pid: 6662, comm: accel-pppd Not tainted 3.2.46.mini #1 Bochs Bochs
[  452.064012] RIP: 0010:[<ffffffff81059f6e>]  [<ffffffff81059f6e>] do_raw_spin_lock+0x19/0x1f
[  452.064012] RSP: 0018:ffff8800b6e83ba0  EFLAGS: 00000297
[  452.064012] RAX: 000000000000aaa9 RBX: ffff8800b6e83b40 RCX: 0000000000000002
[  452.064012] RDX: 00000000000000aa RSI: 000000000000000a RDI: ffff8800745c8110
[  452.064012] RBP: ffff8800b6e83ba0 R08: 000000000000c802 R09: 000000000000001c
[  452.064012] R10: ffff880071096c4e R11: 0000000000000006 R12: ffff8800b6e83b18
[  452.064012] R13: ffffffff8125d51e R14: ffff8800b6e83ba0 R15: ffff880072a589c0
[  452.064012] FS:  00007fdc0b81e700(0000) GS:ffff8800b6e80000(0000) knlGS:0000000000000000
[  452.064012] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  452.064012] CR2: 0000000000625208 CR3: 0000000074404000 CR4: 00000000000006a0
[  452.064012] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  452.064012] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  452.064012] Process accel-pppd (pid: 6662, threadinfo ffff88007129a000, task ffff8800744f7410)
[  452.064012] Stack:
[  452.064012]  ffff8800b6e83bb0 ffffffff81256559 ffff8800b6e83bc0 ffffffff8121c64a
[  452.064012]  ffff8800b6e83bf0 ffffffff8121ec7a ffff880072a589c0 ffff880071096c62
[  452.064012]  0000000000000011 ffffffff81430024 ffff8800b6e83c80 ffffffff8121f276
[  452.064012] Call Trace:
[  452.064012]  <IRQ>
[  452.064012]  [<ffffffff81256559>] _raw_spin_lock+0xe/0x10
[  452.064012]  [<ffffffff8121c64a>] spin_lock+0x9/0xb
[  452.064012]  [<ffffffff8121ec7a>] udp_queue_rcv_skb+0x186/0x269
[  452.064012]  [<ffffffff8121f276>] __udp4_lib_rcv+0x297/0x4ae
[  452.064012]  [<ffffffff8121c178>] ? raw_rcv+0xe9/0xf0
[  452.064012]  [<ffffffff8121f4a7>] udp_rcv+0x1a/0x1c
[  452.064012]  [<ffffffff811fe385>] ip_local_deliver_finish+0x12b/0x1a5
[  452.064012]  [<ffffffff811fe54e>] ip_local_deliver+0x53/0x84
[  452.064012]  [<ffffffff811fe1d0>] ip_rcv_finish+0x2bc/0x2f3
[  452.064012]  [<ffffffff811fe78f>] ip_rcv+0x210/0x269
[  452.064012]  [<ffffffff8101911e>] ? kvm_clock_get_cycles+0x9/0xb
[  452.064012]  [<ffffffff811d88cd>] __netif_receive_skb+0x3a5/0x3f7
[  452.064012]  [<ffffffff811d8eba>] netif_receive_skb+0x57/0x5e
[  452.064012]  [<ffffffff811cf30f>] ? __netdev_alloc_skb+0x1f/0x3b
[  452.064012]  [<ffffffffa0049126>] virtnet_poll+0x4ba/0x5a4 [virtio_net]
[  452.064012]  [<ffffffff811d9417>] net_rx_action+0x73/0x184
[  452.064012]  [<ffffffffa01b2cc2>] ? l2tp_xmit_skb+0x27a/0x4ac [l2tp_core]
[  452.064012]  [<ffffffff810343b9>] __do_softirq+0xc3/0x1a8
[  452.064012]  [<ffffffff81013b56>] ? ack_APIC_irq+0x10/0x12
[  452.064012]  [<ffffffff81256559>] ? _raw_spin_lock+0xe/0x10
[  452.064012]  [<ffffffff8125e0ac>] call_softirq+0x1c/0x26
[  452.064012]  [<ffffffff81003587>] do_softirq+0x45/0x82
[  452.064012]  [<ffffffff81034667>] irq_exit+0x42/0x9c
[  452.064012]  [<ffffffff8125e146>] do_IRQ+0x8e/0xa5
[  452.064012]  [<ffffffff8125676e>] common_interrupt+0x6e/0x6e
[  452.064012]  <EOI>
[  452.064012]  [<ffffffff810b82a1>] ? kfree+0x8a/0xa3
[  452.064012]  [<ffffffffa01b2cc2>] ? l2tp_xmit_skb+0x27a/0x4ac [l2tp_core]
[  452.064012]  [<ffffffffa01b2c25>] ? l2tp_xmit_skb+0x1dd/0x4ac [l2tp_core]
[  452.064012]  [<ffffffffa01c2d36>] pppol2tp_sendmsg+0x15e/0x19c [l2tp_ppp]
[  452.064012]  [<ffffffff811c7872>] __sock_sendmsg_nosec+0x22/0x24
[  452.064012]  [<ffffffff811c83bd>] sock_sendmsg+0xa1/0xb6
[  452.064012]  [<ffffffff81254e88>] ? __schedule+0x5c1/0x616
[  452.064012]  [<ffffffff8103c7c6>] ? __dequeue_signal+0xb7/0x10c
[  452.064012]  [<ffffffff810bbd21>] ? fget_light+0x75/0x89
[  452.064012]  [<ffffffff811c8444>] ? sockfd_lookup_light+0x20/0x56
[  452.064012]  [<ffffffff811c9b34>] sys_sendto+0x10c/0x13b
[  452.064012]  [<ffffffff8125cac2>] system_call_fastpath+0x16/0x1b
[  452.064012] Code: 89 e5 72 0c 31 c0 48 81 ff 45 66 25 81 0f 92 c0 5d c3 55 b8 00 01 00 00 48 89 e5 f0 66 0f c1 07 0f b6 d4 38 d0 74 06 f3 90 8a 07 <eb> f6 5d c3 90 90 55 48 89 e5 9c 58 0f 1f 44 00 00 5d c3 55 48
[  452.064012] Call Trace:
[  452.064012]  <IRQ>  [<ffffffff81256559>] _raw_spin_lock+0xe/0x10
[  452.064012]  [<ffffffff8121c64a>] spin_lock+0x9/0xb
[  452.064012]  [<ffffffff8121ec7a>] udp_queue_rcv_skb+0x186/0x269
[  452.064012]  [<ffffffff8121f276>] __udp4_lib_rcv+0x297/0x4ae
[  452.064012]  [<ffffffff8121c178>] ? raw_rcv+0xe9/0xf0
[  452.064012]  [<ffffffff8121f4a7>] udp_rcv+0x1a/0x1c
[  452.064012]  [<ffffffff811fe385>] ip_local_deliver_finish+0x12b/0x1a5
[  452.064012]  [<ffffffff811fe54e>] ip_local_deliver+0x53/0x84
[  452.064012]  [<ffffffff811fe1d0>] ip_rcv_finish+0x2bc/0x2f3
[  452.064012]  [<ffffffff811fe78f>] ip_rcv+0x210/0x269
[  452.064012]  [<ffffffff8101911e>] ? kvm_clock_get_cycles+0x9/0xb
[  452.064012]  [<ffffffff811d88cd>] __netif_receive_skb+0x3a5/0x3f7
[  452.064012]  [<ffffffff811d8eba>] netif_receive_skb+0x57/0x5e
[  452.064012]  [<ffffffff811cf30f>] ? __netdev_alloc_skb+0x1f/0x3b
[  452.064012]  [<ffffffffa0049126>] virtnet_poll+0x4ba/0x5a4 [virtio_net]
[  452.064012]  [<ffffffff811d9417>] net_rx_action+0x73/0x184
[  452.064012]  [<ffffffffa01b2cc2>] ? l2tp_xmit_skb+0x27a/0x4ac [l2tp_core]
[  452.064012]  [<ffffffff810343b9>] __do_softirq+0xc3/0x1a8
[  452.064012]  [<ffffffff81013b56>] ? ack_APIC_irq+0x10/0x12
[  452.064012]  [<ffffffff81256559>] ? _raw_spin_lock+0xe/0x10
[  452.064012]  [<ffffffff8125e0ac>] call_softirq+0x1c/0x26
[  452.064012]  [<ffffffff81003587>] do_softirq+0x45/0x82
[  452.064012]  [<ffffffff81034667>] irq_exit+0x42/0x9c
[  452.064012]  [<ffffffff8125e146>] do_IRQ+0x8e/0xa5
[  452.064012]  [<ffffffff8125676e>] common_interrupt+0x6e/0x6e
[  452.064012]  <EOI>  [<ffffffff810b82a1>] ? kfree+0x8a/0xa3
[  452.064012]  [<ffffffffa01b2cc2>] ? l2tp_xmit_skb+0x27a/0x4ac [l2tp_core]
[  452.064012]  [<ffffffffa01b2c25>] ? l2tp_xmit_skb+0x1dd/0x4ac [l2tp_core]
[  452.064012]  [<ffffffffa01c2d36>] pppol2tp_sendmsg+0x15e/0x19c [l2tp_ppp]
[  452.064012]  [<ffffffff811c7872>] __sock_sendmsg_nosec+0x22/0x24
[  452.064012]  [<ffffffff811c83bd>] sock_sendmsg+0xa1/0xb6
[  452.064012]  [<ffffffff81254e88>] ? __schedule+0x5c1/0x616
[  452.064012]  [<ffffffff8103c7c6>] ? __dequeue_signal+0xb7/0x10c
[  452.064012]  [<ffffffff810bbd21>] ? fget_light+0x75/0x89
[  452.064012]  [<ffffffff811c8444>] ? sockfd_lookup_light+0x20/0x56
[  452.064012]  [<ffffffff811c9b34>] sys_sendto+0x10c/0x13b
[  452.064012]  [<ffffffff8125cac2>] system_call_fastpath+0x16/0x1b

Reported-by: François Cachereul <f.cachereul@alphalink.fr>
Tested-by: François Cachereul <f.cachereul@alphalink.fr>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:02 -08:00
Christophe Gouault
a77db44038 vti: get rid of nf mark rule in prerouting
[ Upstream commit 7263a5187f ]

This patch fixes and improves the use of vti interfaces (while
lightly changing the way of configuring them).

Currently:

- it is necessary to identify and mark inbound IPsec
  packets destined to each vti interface, via netfilter rules in
  the mangle table at prerouting hook.

- the vti module cannot retrieve the right tunnel in input since
  commit b9959fd3: vti tunnels all have an i_key, but the tunnel lookup
  is done with flag TUNNEL_NO_KEY, so there no chance to retrieve them.

- the i_key is used by the outbound processing as a mark to lookup
  for the right SP and SA bundle.

This patch uses the o_key to store the vti mark (instead of i_key) and
enables:

- to avoid the need for previously marking the inbound skbuffs via a
  netfilter rule.
- to properly retrieve the right tunnel in input, only based on the IPsec
  packet outer addresses.
- to properly perform an inbound policy check (using the tunnel o_key
  as a mark).
- to properly perform an outbound SPD and SAD lookup (using the tunnel
  o_key as a mark).
- to keep the current mark of the skbuff. The skbuff mark is neither
  used nor changed by the vti interface. Only the vti interface o_key
  is used.

SAs have a wildcard mark.
SPs have a mark equal to the vti interface o_key.

The vti interface must be created as follows (i_key = 0, o_key = mark):

   ip link add vti1 mode vti local 1.1.1.1 remote 2.2.2.2 okey 1

The SPs attached to vti1 must be created as follows (mark = vti1 o_key):

   ip xfrm policy add dir out mark 1 tmpl src 1.1.1.1 dst 2.2.2.2 \
      proto esp mode tunnel
   ip xfrm policy add dir in  mark 1 tmpl src 2.2.2.2 dst 1.1.1.1 \
      proto esp mode tunnel

The SAs are created with the default wildcard mark. There is no
distinction between global vs. vti SAs. Just their addresses will
possibly link them to a vti interface:

   ip xfrm state add src 1.1.1.1 dst 2.2.2.2 proto esp spi 1000 mode tunnel \
                 enc "cbc(aes)" "azertyuiopqsdfgh"

   ip xfrm state add src 2.2.2.2 dst 1.1.1.1 proto esp spi 2000 mode tunnel \
                 enc "cbc(aes)" "sqbdhgqsdjqjsdfh"

To avoid matching "global" (not vti) SPs in vti interfaces, global SPs
should no use the default wildcard mark, but explicitly match mark 0.

To avoid a double SPD lookup in input and output (in global and vti SPDs),
the NOPOLICY and NOXFRM options should be set on the vti interfaces:

   echo 1 > /proc/sys/net/ipv4/conf/vti1/disable_policy
   echo 1 > /proc/sys/net/ipv4/conf/vti1/disable_xfrm

The outgoing traffic is steered to vti1 by a route via the vti interface:

   ip route add 192.168.0.0/16 dev vti1

The incoming IPsec traffic is steered to vti1 because its outer addresses
match the vti1 tunnel configuration.

Signed-off-by: Christophe Gouault <christophe.gouault@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:02 -08:00
Marc Kleine-Budde
4c1f32d2d7 net: vlan: fix nlmsg size calculation in vlan_get_size()
[ Upstream commit c33a39c575 ]

This patch fixes the calculation of the nlmsg size, by adding the missing
nla_total_size().

Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:02 -08:00
Paul Durrant
f495ddc46f xen-netback: Don't destroy the netdev until the vif is shut down
[ upstream commit id: 279f438e36 ]

Without this patch, if a frontend cycles through states Closing
and Closed (which Windows frontends need to do) then the netdev
will be destroyed and requires re-invocation of hotplug scripts
to restore state before the frontend can move to Connected. Thus
when udev is not in use the backend gets stuck in InitWait.

With this patch, the netdev is left alone whilst the backend is
still online and is only de-registered and freed just prior to
destroying the vif (which is also nicely symmetrical with the
netdev allocation and registration being done during probe) so
no re-invocation of hotplug scripts is required.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:01 -08:00
Fabio Estevam
b9396c4c9e net: secure_seq: Fix warning when CONFIG_IPV6 and CONFIG_INET are not selected
[ Upstream commit cb03db9d0e ]

net_secret() is only used when CONFIG_IPV6 or CONFIG_INET are selected.

Building a defconfig with both of these symbols unselected (Using the ARM
at91sam9rl_defconfig, for example) leads to the following build warning:

$ make at91sam9rl_defconfig
#
# configuration written to .config
#

$ make net/core/secure_seq.o
scripts/kconfig/conf --silentoldconfig Kconfig
  CHK     include/config/kernel.release
  CHK     include/generated/uapi/linux/version.h
  CHK     include/generated/utsrelease.h
make[1]: `include/generated/mach-types.h' is up to date.
  CALL    scripts/checksyscalls.sh
  CC      net/core/secure_seq.o
net/core/secure_seq.c:17:13: warning: 'net_secret_init' defined but not used [-Wunused-function]

Fix this warning by protecting the definition of net_secret() with these
symbols.

Reported-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:01 -08:00
Marc Kleine-Budde
42fc155b9f can: dev: fix nlmsg size calculation in can_get_size()
[ Upstream commit fe119a05f8 ]

This patch fixes the calculation of the nlmsg size, by adding the missing
nla_total_size().

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:01 -08:00
Jiri Benc
b15e22da6e ipv4: fix ineffective source address selection
[ Upstream commit 0a7e226090 ]

When sending out multicast messages, the source address in inet->mc_addr is
ignored and rewritten by an autoselected one. This is caused by a typo in
commit 813b3b5db8 ("ipv4: Use caller's on-stack flowi as-is in output
route lookups").

Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:01 -08:00
Mathias Krause
df6ae0dc31 proc connector: fix info leaks
[ Upstream commit e727ca82e0 ]

Initialize event_data for all possible message types to prevent leaking
kernel stack contents to userland (up to 20 bytes). Also set the flags
member of the connector message to 0 to prevent leaking two more stack
bytes this way.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:01 -08:00
Dan Carpenter
2e8d97ab1f net: heap overflow in __audit_sockaddr()
[ Upstream commit 1661bf364a ]

We need to cap ->msg_namelen or it leads to a buffer overflow when we
to the memcpy() in __audit_sockaddr().  It requires CAP_AUDIT_CONTROL to
exploit this bug.

The call tree is:
___sys_recvmsg()
  move_addr_to_user()
    audit_sockaddr()
      __audit_sockaddr()

Reported-by: Jüri Aedla <juri.aedla@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:00 -08:00
Sebastian Hesselbarth
b24b4a82fc net: mv643xx_eth: fix orphaned statistics timer crash
[ Upstream commit f564412c93 ]

The periodic statistics timer gets started at port _probe() time, but
is stopped on _stop() only. In a modular environment, this can cause
the timer to access already deallocated memory, if the module is unloaded
without starting the eth device. To fix this, we add the timer right
before the port is started, instead of at _probe() time.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:00 -08:00
Sebastian Hesselbarth
85cd02136d net: mv643xx_eth: update statistics timer from timer context only
[ Upstream commit 041b4ddb84 ]

Each port driver installs a periodic timer to update port statistics
by calling mib_counters_update. As mib_counters_update is also called
from non-timer context, we should not reschedule the timer there but
rather move it to timer-only context.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:00 -08:00
David S. Miller
d980ed627b l2tp: Fix build warning with ipv6 disabled.
[ Upstream commit 8d8a51e26a ]

net/l2tp/l2tp_core.c: In function ‘l2tp_verify_udp_checksum’:
net/l2tp/l2tp_core.c:499:22: warning: unused variable ‘tunnel’ [-Wunused-variable]

Create a helper "l2tp_tunnel()" to facilitate this, and as a side
effect get rid of a bunch of unnecessary void pointer casts.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:00 -08:00
François CACHEREUL
bd83cd7707 l2tp: fix kernel panic when using IPv4-mapped IPv6 addresses
[ Upstream commit e18503f41f ]

IPv4 mapped addresses cause kernel panic.
The patch juste check whether the IPv6 address is an IPv4 mapped
address. If so, use IPv4 API instead of IPv6.

[  940.026915] general protection fault: 0000 [#1]
[  940.026915] Modules linked in: l2tp_ppp l2tp_netlink l2tp_core pppox ppp_generic slhc loop psmouse
[  940.026915] CPU: 0 PID: 3184 Comm: memcheck-amd64- Not tainted 3.11.0+ #1
[  940.026915] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[  940.026915] task: ffff880007130e20 ti: ffff88000737e000 task.ti: ffff88000737e000
[  940.026915] RIP: 0010:[<ffffffff81333780>]  [<ffffffff81333780>] ip6_xmit+0x276/0x326
[  940.026915] RSP: 0018:ffff88000737fd28  EFLAGS: 00010286
[  940.026915] RAX: c748521a75ceff48 RBX: ffff880000c30800 RCX: 0000000000000000
[  940.026915] RDX: ffff88000075cc4e RSI: 0000000000000028 RDI: ffff8800060e5a40
[  940.026915] RBP: ffff8800060e5a40 R08: 0000000000000000 R09: ffff88000075cc90
[  940.026915] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88000737fda0
[  940.026915] R13: 0000000000000000 R14: 0000000000002000 R15: ffff880005d3b580
[  940.026915] FS:  00007f163dc5e800(0000) GS:ffffffff81623000(0000) knlGS:0000000000000000
[  940.026915] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  940.026915] CR2: 00000004032dc940 CR3: 0000000005c25000 CR4: 00000000000006f0
[  940.026915] Stack:
[  940.026915]  ffff88000075cc4e ffffffff81694e90 ffff880000c30b38 0000000000000020
[  940.026915]  11000000523c4bac ffff88000737fdb4 0000000000000000 ffff880000c30800
[  940.026915]  ffff880005d3b580 ffff880000c30b38 ffff8800060e5a40 0000000000000020
[  940.026915] Call Trace:
[  940.026915]  [<ffffffff81356cc3>] ? inet6_csk_xmit+0xa4/0xc4
[  940.026915]  [<ffffffffa0038535>] ? l2tp_xmit_skb+0x503/0x55a [l2tp_core]
[  940.026915]  [<ffffffff812b8d3b>] ? pskb_expand_head+0x161/0x214
[  940.026915]  [<ffffffffa003e91d>] ? pppol2tp_xmit+0xf2/0x143 [l2tp_ppp]
[  940.026915]  [<ffffffffa00292e0>] ? ppp_channel_push+0x36/0x8b [ppp_generic]
[  940.026915]  [<ffffffffa00293fe>] ? ppp_write+0xaf/0xc5 [ppp_generic]
[  940.026915]  [<ffffffff8110ead4>] ? vfs_write+0xa2/0x106
[  940.026915]  [<ffffffff8110edd6>] ? SyS_write+0x56/0x8a
[  940.026915]  [<ffffffff81378ac0>] ? system_call_fastpath+0x16/0x1b
[  940.026915] Code: 00 49 8b 8f d8 00 00 00 66 83 7c 11 02 00 74 60 49
8b 47 58 48 83 e0 fe 48 8b 80 18 01 00 00 48 85 c0 74 13 48 8b 80 78 02
00 00 <48> ff 40 28 41 8b 57 68 48 01 50 30 48 8b 54 24 08 49 c7 c1 51
[  940.026915] RIP  [<ffffffff81333780>] ip6_xmit+0x276/0x326
[  940.026915]  RSP <ffff88000737fd28>
[  940.057945] ---[ end trace be8aba9a61c8b7f3 ]---
[  940.058583] Kernel panic - not syncing: Fatal exception in interrupt

Signed-off-by: François CACHEREUL <f.cachereul@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:00 -08:00
Eric Dumazet
53d384ae6a net: do not call sock_put() on TIMEWAIT sockets
[ Upstream commit 80ad1d61e7 ]

commit 3ab5aee7fe ("net: Convert TCP & DCCP hash tables to use RCU /
hlist_nulls") incorrectly used sock_put() on TIMEWAIT sockets.

We should instead use inet_twsk_put()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:00 -08:00
Yuchung Cheng
d8ac0f178f tcp: fix incorrect ca_state in tail loss probe
[ Upstream commit 031afe4990 ]

On receiving an ACK that covers the loss probe sequence, TLP
immediately sets the congestion state to Open, even though some packets
are not recovered and retransmisssion are on the way.  The later ACks
may trigger a WARN_ON check in step D of tcp_fastretrans_alert(), e.g.,
https://bugzilla.redhat.com/show_bug.cgi?id=989251

The fix is to follow the similar procedure in recovery by calling
tcp_try_keep_open(). The sender switches to Open state if no packets
are retransmissted. Otherwise it goes to Disorder and let subsequent
ACKs move the state to Recovery or Open.

Reported-By: Michael Sterrett <michael@sterretts.net>
Tested-By: Dormando <dormando@rydia.net>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:30:59 -08:00
Eric Dumazet
a50b0399e6 tcp: do not forget FIN in tcp_shifted_skb()
[ Upstream commit 5e8a402f83 ]

Yuchung found following problem :

 There are bugs in the SACK processing code, merging part in
 tcp_shift_skb_data(), that incorrectly resets or ignores the sacked
 skbs FIN flag. When a receiver first SACK the FIN sequence, and later
 throw away ofo queue (e.g., sack-reneging), the sender will stop
 retransmitting the FIN flag, and hangs forever.

Following packetdrill test can be used to reproduce the bug.

$ cat sack-merge-bug.pkt
`sysctl -q net.ipv4.tcp_fack=0`

// Establish a connection and send 10 MSS.
0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+.000 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
+.000 bind(3, ..., ...) = 0
+.000 listen(3, 1) = 0

+.050 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7>
+.000 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 6>
+.001 < . 1:1(0) ack 1 win 1024
+.000 accept(3, ..., ...) = 4

+.100 write(4, ..., 12000) = 12000
+.000 shutdown(4, SHUT_WR) = 0
+.000 > . 1:10001(10000) ack 1
+.050 < . 1:1(0) ack 2001 win 257
+.000 > FP. 10001:12001(2000) ack 1
+.050 < . 1:1(0) ack 2001 win 257 <sack 10001:11001,nop,nop>
+.050 < . 1:1(0) ack 2001 win 257 <sack 10001:12002,nop,nop>
// SACK reneg
+.050 < . 1:1(0) ack 12001 win 257
+0 %{ print "unacked: ",tcpi_unacked }%
+5 %{ print "" }%

First, a typo inverted left/right of one OR operation, then
code forgot to advance end_seq if the merged skb carried FIN.

Bug was added in 2.6.29 by commit 832d11c5cd
("tcp: Try to restore large SKBs while SACK processing")

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:30:59 -08:00
Eric Dumazet
b81908e15f tcp: must unclone packets before mangling them
[ Upstream commit c52e2421f7 ]

TCP stack should make sure it owns skbs before mangling them.

We had various crashes using bnx2x, and it turned out gso_size
was cleared right before bnx2x driver was populating TC descriptor
of the _previous_ packet send. TCP stack can sometime retransmit
packets that are still in Qdisc.

Of course we could make bnx2x driver more robust (using
ACCESS_ONCE(shinfo->gso_size) for example), but the bug is TCP stack.

We have identified two points where skb_unclone() was needed.

This patch adds a WARN_ON_ONCE() to warn us if we missed another
fix of this kind.

Kudos to Neal for finding the root cause of this bug. Its visible
using small MSS.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:30:59 -08:00
Eric Dumazet
0ae5f47eff tcp: TSQ can use a dynamic limit
[ Upstream commit c9eeec26e3 ]

When TCP Small Queues was added, we used a sysctl to limit amount of
packets queues on Qdisc/device queues for a given TCP flow.

Problem is this limit is either too big for low rates, or too small
for high rates.

Now TCP stack has rate estimation in sk->sk_pacing_rate, and TSO
auto sizing, it can better control number of packets in Qdisc/device
queues.

New limit is two packets or at least 1 to 2 ms worth of packets.

Low rates flows benefit from this patch by having even smaller
number of packets in queues, allowing for faster recovery,
better RTT estimations.

High rates flows benefit from this patch by allowing more than 2 packets
in flight as we had reports this was a limiting factor to reach line
rate. [ In particular if TX completion is delayed because of coalescing
parameters ]

Example for a single flow on 10Gbp link controlled by FQ/pacing

14 packets in flight instead of 2

$ tc -s -d qd
qdisc fq 8001: dev eth0 root refcnt 32 limit 10000p flow_limit 100p
buckets 1024 quantum 3028 initial_quantum 15140
 Sent 1168459366606 bytes 771822841 pkt (dropped 0, overlimits 0
requeues 6822476)
 rate 9346Mbit 771713pps backlog 953820b 14p requeues 6822476
  2047 flow, 2046 inactive, 1 throttled, delay 15673 ns
  2372 gc, 0 highprio, 0 retrans, 9739249 throttled, 0 flows_plimit

Note that sk_pacing_rate is currently set to twice the actual rate, but
this might be refined in the future when a flow is in congestion
avoidance.

Additional change : skb->destructor should be set to tcp_wfree().

A future patch (for linux 3.13+) might remove tcp_limit_output_bytes

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:30:59 -08:00
Eric Dumazet
5e25ba5003 tcp: TSO packets automatic sizing
[ Upstream commits 6d36824e730f247b602c90e8715a792003e3c5a7,
  02cf4ebd82, and parts of
  7eec4174ff ]

After hearing many people over past years complaining against TSO being
bursty or even buggy, we are proud to present automatic sizing of TSO
packets.

One part of the problem is that tcp_tso_should_defer() uses an heuristic
relying on upcoming ACKS instead of a timer, but more generally, having
big TSO packets makes little sense for low rates, as it tends to create
micro bursts on the network, and general consensus is to reduce the
buffering amount.

This patch introduces a per socket sk_pacing_rate, that approximates
the current sending rate, and allows us to size the TSO packets so
that we try to send one packet every ms.

This field could be set by other transports.

Patch has no impact for high speed flows, where having large TSO packets
makes sense to reach line rate.

For other flows, this helps better packet scheduling and ACK clocking.

This patch increases performance of TCP flows in lossy environments.

A new sysctl (tcp_min_tso_segs) is added, to specify the
minimal size of a TSO packet (default being 2).

A follow-up patch will provide a new packet scheduler (FQ), using
sk_pacing_rate as an input to perform optional per flow pacing.

This explains why we chose to set sk_pacing_rate to twice the current
rate, allowing 'slow start' ramp up.

sk_pacing_rate = 2 * cwnd * mss / srtt

v2: Neal Cardwell reported a suspect deferring of last two segments on
initial write of 10 MSS, I had to change tcp_tso_should_defer() to take
into account tp->xmit_size_goal_segs

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Van Jacobson <vanj@google.com>
Cc: Tom Herbert <therbert@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:30:59 -08:00
Greg Kroah-Hartman
14e9c7db46 Linux 3.10.17 v3.10.17 2013-10-18 10:44:19 -07:00
Linn Crosetto
954acd2b6d x86: avoid remapping data in parse_setup_data()
commit 30e46b574a upstream.

Type SETUP_PCI, added by setup_efi_pci(), may advertise a ROM size
larger than early_memremap() is able to handle, which is currently
limited to 256kB. If this occurs it leads to a NULL dereference in
parse_setup_data().

To avoid this, remap the setup_data header and allow parsing functions
for individual types to handle their own data remapping.

Signed-off-by: Linn Crosetto <linn@hp.com>
Link: http://lkml.kernel.org/r/1376430401-67445-1-git-send-email-linn@hp.com
Acked-by: Yinghai Lu <yinghai@kernel.org>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-18 07:45:48 -07:00
Davidlohr Bueso
3232569ecd ipc,msg: prevent race with rmid in msgsnd,msgrcv
commit 4271b05a22 upstream.

This fixes a race in both msgrcv() and msgsnd() between finding the msg
and actually dealing with the queue, as another thread can delete shmid
underneath us if we are preempted before acquiring the
kern_ipc_perm.lock.

Manfred illustrates this nicely:

Assume a preemptible kernel that is preempted just after

    msq = msq_obtain_object_check(ns, msqid)

in do_msgrcv().  The only lock that is held is rcu_read_lock().

Now the other thread processes IPC_RMID.  When the first task is
resumed, then it will happily wait for messages on a deleted queue.

Fix this by checking for if the queue has been deleted after taking the
lock.

Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Reported-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-18 07:45:48 -07:00
Manfred Spraul
e556ea0191 ipc/sem.c: update sem_otime for all operations
commit 0e8c665699 upstream.

In commit 0a2b9d4c79 ("ipc/sem.c: move wake_up_process out of the
spinlock section"), the update of semaphore's sem_otime(last semop time)
was moved to one central position (do_smart_update).

But since do_smart_update() is only called for operations that modify
the array, this means that wait-for-zero semops do not update sem_otime
anymore.

The fix is simple:
Non-alter operations must update sem_otime.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Reported-by: Jia He <jiakernel@gmail.com>
Tested-by: Jia He <jiakernel@gmail.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-18 07:45:48 -07:00
Manfred Spraul
83aeb6e344 ipc/sem.c: synchronize the proc interface
commit d8c633766a upstream.

The proc interface is not aware of sem_lock(), it instead calls
ipc_lock_object() directly.  This means that simple semop() operations
can run in parallel with the proc interface.  Right now, this is
uncritical, because the implementation doesn't do anything that requires
a proper synchronization.

But it is dangerous and therefore should be fixed.

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-18 07:45:48 -07:00
Manfred Spraul
901f6fedc5 ipc/sem.c: optimize sem_lock()
commit 6d07b68ce1 upstream.

Operations that need access to the whole array must guarantee that there
are no simple operations ongoing.  Right now this is achieved by
spin_unlock_wait(sem->lock) on all semaphores.

If complex_count is nonzero, then this spin_unlock_wait() is not
necessary, because it was already performed in the past by the thread
that increased complex_count and even though sem_perm.lock was dropped
inbetween, no simple operation could have started, because simple
operations cannot start when complex_count is non-zero.

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Mike Galbraith <bitbucket@online.de>
Cc: Rik van Riel <riel@redhat.com>
Reviewed-by: Davidlohr Bueso <davidlohr@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-18 07:45:48 -07:00
Manfred Spraul
184076a9f9 ipc/sem.c: fix race in sem_lock()
commit 5e9d527591 upstream.

The exclusion of complex operations in sem_lock() is insufficient: after
acquiring the per-semaphore lock, a simple op must first check that
sem_perm.lock is not locked and only after that test check
complex_count.  The current code does it the other way around - and that
creates a race.  Details are below.

The patch is a complete rewrite of sem_lock(), based in part on the code
from Mike Galbraith.  It removes all gotos and all loops and thus the
risk of livelocks.

I have tested the patch (together with the next one) on my i3 laptop and
it didn't cause any problems.

The bug is probably also present in 3.10 and 3.11, but for these kernels
it might be simpler just to move the test of sma->complex_count after
the spin_is_locked() test.

Details of the bug:

Assume:
 - sma->complex_count = 0.
 - Thread 1: semtimedop(complex op that must sleep)
 - Thread 2: semtimedop(simple op).

Pseudo-Trace:

Thread 1: sem_lock(): acquire sem_perm.lock
Thread 1: sem_lock(): check for ongoing simple ops
			Nothing ongoing, thread 2 is still before sem_lock().
Thread 1: try_atomic_semop()
	<<< preempted.

Thread 2: sem_lock():
        static inline int sem_lock(struct sem_array *sma, struct sembuf *sops,
                                      int nsops)
        {
                int locknum;
         again:
                if (nsops == 1 && !sma->complex_count) {
                        struct sem *sem = sma->sem_base + sops->sem_num;

                        /* Lock just the semaphore we are interested in. */
                        spin_lock(&sem->lock);

                        /*
                         * If sma->complex_count was set while we were spinning,
                         * we may need to look at things we did not lock here.
                         */
                        if (unlikely(sma->complex_count)) {
                                spin_unlock(&sem->lock);
                                goto lock_array;
                        }
        <<<<<<<<<
	<<< complex_count is still 0.
	<<<
        <<< Here it is preempted
        <<<<<<<<<

Thread 1: try_atomic_semop() returns, notices that it must sleep.
Thread 1: increases sma->complex_count.
Thread 1: drops sem_perm.lock
Thread 2:
                /*
                 * Another process is holding the global lock on the
                 * sem_array; we cannot enter our critical section,
                 * but have to wait for the global lock to be released.
                 */
                if (unlikely(spin_is_locked(&sma->sem_perm.lock))) {
                        spin_unlock(&sem->lock);
                        spin_unlock_wait(&sma->sem_perm.lock);
                        goto again;
                }
	<<< sem_perm.lock already dropped, thus no "goto again;"

                locknum = sops->sem_num;

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Mike Galbraith <bitbucket@online.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-18 07:45:48 -07:00
Davidlohr Bueso
e84ca33375 ipc: fix race with LSMs
commit 53dad6d3a8 upstream.

Currently, IPC mechanisms do security and auditing related checks under
RCU.  However, since security modules can free the security structure,
for example, through selinux_[sem,msg_queue,shm]_free_security(), we can
race if the structure is freed before other tasks are done with it,
creating a use-after-free condition.  Manfred illustrates this nicely,
for instance with shared mem and selinux:

 -> do_shmat calls rcu_read_lock()
 -> do_shmat calls shm_object_check().
     Checks that the object is still valid - but doesn't acquire any locks.
     Then it returns.
 -> do_shmat calls security_shm_shmat (e.g. selinux_shm_shmat)
 -> selinux_shm_shmat calls ipc_has_perm()
 -> ipc_has_perm accesses ipc_perms->security

shm_close()
 -> shm_close acquires rw_mutex & shm_lock
 -> shm_close calls shm_destroy
 -> shm_destroy calls security_shm_free (e.g. selinux_shm_free_security)
 -> selinux_shm_free_security calls ipc_free_security(&shp->shm_perm)
 -> ipc_free_security calls kfree(ipc_perms->security)

This patch delays the freeing of the security structures after all RCU
readers are done.  Furthermore it aligns the security life cycle with
that of the rest of IPC - freeing them based on the reference counter.
For situations where we need not free security, the current behavior is
kept.  Linus states:

 "... the old behavior was suspect for another reason too: having the
  security blob go away from under a user sounds like it could cause
  various other problems anyway, so I think the old code was at least
  _prone_ to bugs even if it didn't have catastrophic behavior."

I have tested this patch with IPC testcases from LTP on both my
quad-core laptop and on a 64 core NUMA server.  In both cases selinux is
enabled, and tests pass for both voluntary and forced preemption models.
While the mentioned races are theoretical (at least no one as reported
them), I wanted to make sure that this new logic doesn't break anything
we weren't aware of.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Acked-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-18 07:45:48 -07:00
Davidlohr Bueso
c42107e682 ipc: drop ipc_lock_check
commit 20b8875abc upstream.

No remaining users, we now use ipc_obtain_object_check().

Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-18 07:45:48 -07:00
Davidlohr Bueso
1129a4810a ipc, shm: drop shm_lock_check
commit 7a25dd9e04 upstream.

This function was replaced by a the lockless shm_obtain_object_check(),
and no longer has any users.

Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-18 07:45:48 -07:00
Davidlohr Bueso
ffa02e67ef ipc: drop ipc_lock_by_ptr
commit 32a2750010 upstream.

After previous cleanups and optimizations, this function is no longer
heavily used and we don't have a good reason to keep it.  Update the few
remaining callers and get rid of it.

Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-18 07:45:48 -07:00
Davidlohr Bueso
48ec782ce3 ipc, shm: guard against non-existant vma in shmdt(2)
commit 530fcd16d8 upstream.

When !CONFIG_MMU there's a chance we can derefence a NULL pointer when the
VM area isn't found - check the return value of find_vma().

Also, remove the redundant -EINVAL return: retval is set to the proper
return code and *only* changed to 0, when we actually unmap the segments.

Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-18 07:45:48 -07:00
Davidlohr Bueso
a5daa172ff ipc: document general ipc locking scheme
commit 05603c44a7 upstream.

As suggested by Andrew, add a generic initial locking scheme used
throughout all sysv ipc mechanisms.  Documenting the ids rwsem, how rcu
can be enough to do the initial checks and when to actually acquire the
kern_ipc_perm.lock spinlock.

I found that adding it to util.c was generic enough.

Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-18 07:45:48 -07:00