Add SPDX license identifiers to all files which:
- Have no license information of any form
- Have MODULE_LICENCE("GPL*") inside which was used in the initial
scan/conversion to ignore the file
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Rework smc_conn_create() to always return a valid DECLINE reason code.
This removes the need to translate the return codes on 4 different
places and allows to easily add more detailed return codes by changing
smc_conn_create() only.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rework smc_listen_work() to provide improved reason codes when an
SMC connection is declined. This allows better debugging on user side.
This also adds 3 more detailed reason codes in smc_clc.h to indicate
what type of device was not found (ism or rdma or both), or if ism
cannot talk to the peer.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In smc_listen_work() the variables rc and reason_code are defined which
have the same meaning. Eliminate reason_code in favor of the shorter
name rc. No functional changes.
Rename the functions smc_check_ism() and smc_check_rdma() into
smc_find_ism_device() and smc_find_rdma_device() to make there purpose
more clear. No functional changes.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The vlan_id of the underlying CLC socket was retrieved two times
during processing of the listen handshaking. Change this to get the
vlan id one time in connect and in listen processing, and reuse the id.
And add a new CLC DECLINE return code for the case when the retrieval
of the vlan id failed.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
During initialization of an SMC socket a lot of function parameters need
to get passed down the function call path. Consolidate the parameters
in a helper struct so there are less enough parameters to get all passed
by register.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The check for a matching ip prefix and subnet was only done for SMC-R
in smc_listen_rdma_check() but not when an SMC-D connection was
possible. Rename the function into smc_listen_prfx_check() and move its
call to a place where it is called for both SMC variants.
And add a new CLC DECLINE reason for the case when the IP prefix or
subnet check fails so the reason for the failing SMC connection can be
found out more easily.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For nonblocking sockets move the kernel_connect() from the connect
worker into the initial smc_connect part to return kernel_connect()
errors other than -EINPROGRESS to user space.
Reviewed-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit <26d92e951fe0>
("net/smc: move unhash as early as possible in smc_release()")
fixes one occurrence in the smc code, but the same pattern exists
in other places. This patch covers the remaining occurrences and
makes sure, the unhash operation is done before the smc->clcsock is
released. This avoids a potential use-after-free in smc_diag_dump().
Reviewed-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
fcntl(fd, F_SETOWN, getpid()) selects the recipient of SIGURG signals
that are delivered when out-of-band data arrives on socket fd.
If an SMC socket program makes use of such an fcntl() call, it fails
in case of fallback to TCP-mode. In case of fallback the traffic is
processed with the internal TCP socket. Propagating field "file" from the
SMC socket to the internal TCP socket fixes the issue.
Reviewed-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When the clcsock is already released using sock_release() and a pending
smc_listen_work accesses the clcsock than that will fail. Solve this
by canceling and waiting for the work to complete first. Because the
work holds the sock_lock it must make sure that the lock is not hold
before the new helper smc_clcsock_release() is invoked. And before the
smc_listen_work starts working check if the parent listen socket is
still valid, otherwise stop the work early.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds namespace support to the pnet table code. Each network
namespace gets its own pnet table. Infiniband and smcd device pnetids
can only be modified in the initial namespace. In other namespaces they
can still be used as if they were set by the underlying hardware.
Signed-off-by: Hans Wippel <hwippel@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
An ipvlan bug fix in 'net' conflicted with the abstraction away
of the IPV6 specific support in 'net-next'.
Similarly, a bug fix for mlx5 in 'net' conflicted with the flow
action conversion in 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
If SMC client and server connections are both established at the same
time, smc_connect_rdma() cannot send a CLC confirm message while
smc_listen_work() is waiting for one due to lock contention. This can
result in timeouts in smc_clc_wait_msg() and failed SMC connections.
In case of SMC-R, there are two types of LGRs (client and server LGRs)
which can be protected by separate locks. So, this patch splits the LGR
pending lock into two separate locks for client and server to avoid the
locking issue for SMC-R.
Signed-off-by: Hans Wippel <hwippel@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If SMC client and server connections are both established at the same
time, smc_connect_ism() cannot send a CLC confirm message while
smc_listen_work() is waiting for one due to lock contention. This can
result in timeouts in smc_clc_wait_msg() and failed SMC connections.
In case of SMC-D, the LGR pending lock is not needed while
smc_listen_work() is waiting for the CLC confirm message. So, this patch
releases the lock earlier for SMC-D to avoid the locking issue.
Signed-off-by: Hans Wippel <hwippel@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
According to RFC7609 (http://www.rfc-editor.org/info/rfc7609)
first the SMC-R connection is shut down and then the normal TCP
connection FIN processing drives cleanup of the internal TCP connection.
The unconditional release of the clcsock during active socket closing
has to be postponed if the peer has not yet signalled socket closing.
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a socket was connected and is now shut down for read, return 0 to
indicate end of data in recvmsg and splice_read (like TCP) and do not
return ENOTCONN. This behavior is required by the socket api.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Lots of conflicts, by happily all cases of overlapping
changes, parallel adds, things of that nature.
Thanks to Stephen Rothwell, Saeed Mahameed, and others
for their guidance in these resolutions.
Signed-off-by: David S. Miller <davem@davemloft.net>
clcsock can be released while kernel_accept() references it in TCP
listen worker. Also, clcsock needs to wake up before released if TCP
fallback is used and the clcsock is blocked by accept. Add a lock to
safely release clcsock and call kernel_sock_shutdown() to wake up
clcsock from accept in smc_release().
Reported-by: syzbot+0bf2e01269f1274b4b03@syzkaller.appspotmail.com
Reported-by: syzbot+e3132895630f957306bc@syzkaller.appspotmail.com
Signed-off-by: Myungho Jung <mhjungk@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When an rmb is no longer in use by a connection, unregister its rkey at
the remote peer with an LLC DELETE RKEY message. With this change,
unused buffers held in the buffer pool are no longer registered at the
remote peer. They are registered before the buffer is actually used and
unregistered when they are no longer used by a connection.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For easier reading move the unlock of mutex smc_create_lgr_pending into
smc_listen_work(), i.e. into the function the mutex has been locked.
No functional change.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After sending one of the initial LLC messages CONFIRM LINK or
ADD LINK, there is already a wait for the LLC response. It does
not make sense to wait another long time for a CLC DECLINE. Thus
this patch introduces a shorter wait time for these cases.
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If connection initialization fails for the LLC CONFIRM LINK or the
LLC ADD LINK step, fallback to TCP should be enabled. Thus
the negative return code -EAGAIN should switch to a positive timeout
reason code in these cases, and the internal CLC socket should
not have a set sk_err.
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The tcp_listen_worker is already initialized when socket is
created (in smc_sock_alloc()). Get rid of the duplicate
initialization in smc_listen(). No functional change.
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When searching for an existing link group the queue pair number is also
to be taken into consideration. When the SMC server sends a new number
in a CLC packet (keeping all other values equal) then a new link group
is to be created on the SMC client side.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In case of a non-blocking SMC socket, the initial CLC handshake is
performed over a blocking TCP connection in a worker. If the SMC socket
is released, smc_release has to wait for the blocking CLC socket
operations (e.g., kernel_connect) inside the worker.
This patch aborts a CLC connection when the respective non-blocking SMC
socket is released to avoid waiting on socket operations or timeouts.
Signed-off-by: Hans Wippel <hwippel@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts commit dd979b4df8.
This broke tcp_poll for SMC fallback: An AF_SMC socket establishes an
internal TCP socket for the initial handshake with the remote peer.
Whenever the SMC connection can not be established this TCP socket is
used as a fallback. All socket operations on the SMC socket are then
forwarded to the TCP socket. In case of poll, the file->private_data
pointer references the SMC socket because the TCP socket has no file
assigned. This causes tcp_poll to wait on the wrong socket.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Don't check a listen socket for pending urgent data in smc_poll().
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For a failing smc_listen_rdma_finish() smc_listen_decline() is
called. If fallback is possible, the new socket is already enqueued
to be accepted in smc_listen_decline(). Avoid enqueuing a second time
afterwards in this case, otherwise the smc_create_lgr_pending lock
is released twice:
[ 373.463976] WARNING: bad unlock balance detected!
[ 373.463978] 4.18.0-rc7+ #123 Tainted: G O
[ 373.463979] -------------------------------------
[ 373.463980] kworker/1:1/30 is trying to release lock (smc_create_lgr_pending) at:
[ 373.463990] [<000003ff801205fc>] smc_listen_work+0x22c/0x5d0 [smc]
[ 373.463991] but there are no more locks to release!
[ 373.463991]
other info that might help us debug this:
[ 373.463993] 2 locks held by kworker/1:1/30:
[ 373.463994] #0: 00000000772cbaed ((wq_completion)"events"){+.+.}, at: process_one_work+0x1ec/0x6b0
[ 373.464000] #1: 000000003ad0894a ((work_completion)(&new_smc->smc_listen_work)){+.+.}, at: process_one_work+0x1ec/0x6b0
[ 373.464003]
stack backtrace:
[ 373.464005] CPU: 1 PID: 30 Comm: kworker/1:1 Kdump: loaded Tainted: G O 4.18.0-rc7uschi+ #123
[ 373.464007] Hardware name: IBM 2827 H43 738 (LPAR)
[ 373.464010] Workqueue: events smc_listen_work [smc]
[ 373.464011] Call Trace:
[ 373.464015] ([<0000000000114100>] show_stack+0x60/0xd8)
[ 373.464019] [<0000000000a8c9bc>] dump_stack+0x9c/0xd8
[ 373.464021] [<00000000001dcaf8>] print_unlock_imbalance_bug+0xf8/0x108
[ 373.464022] [<00000000001e045c>] lock_release+0x114/0x4f8
[ 373.464025] [<0000000000aa87fa>] __mutex_unlock_slowpath+0x4a/0x300
[ 373.464027] [<000003ff801205fc>] smc_listen_work+0x22c/0x5d0 [smc]
[ 373.464029] [<0000000000197a68>] process_one_work+0x2a8/0x6b0
[ 373.464030] [<0000000000197ec2>] worker_thread+0x52/0x410
[ 373.464033] [<000000000019fd0e>] kthread+0x15e/0x178
[ 373.464035] [<0000000000aaf58a>] kernel_thread_starter+0x6/0xc
[ 373.464052] [<0000000000aaf584>] kernel_thread_starter+0x0/0xc
[ 373.464054] INFO: lockdep is turned off.
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In state SMC_INIT smc_poll() delegates polling to the internal
CLC socket. This means, once the connect worker has finished
its kernel_connect() step, the poll wake-up may occur. This is not
intended. The wake-up should occur from the wake up call in
smc_connect_work() after __smc_connect() has finished.
Thus in state SMC_INIT this patch now calls sock_poll_wait() on the
main SMC socket.
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When an SMC socket is connecting it is decided whether fallback to
TCP is needed. To avoid races between connect and ioctl move the
sock lock before the use_fallback check.
Reported-by: syzbot+5b2cece1a8ecb2ca77d8@syzkaller.appspotmail.com
Reported-by: syzbot+19557374321ca3710990@syzkaller.appspotmail.com
Fixes: 1992d99882 ("net/smc: take sock lock in smc_ioctl()")
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Without setsockopt SO_SNDBUF and SO_RCVBUF settings, the sysctl
defaults net.ipv4.tcp_wmem and net.ipv4.tcp_rmem should be the base
for the sizes of the SMC sndbuf and rcvbuf. Any TCP buffer size
optimizations for servers should be ignored.
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Invoking shutdown for a socket in state SMC_LISTEN does not make
sense. Nevertheless programs like syzbot fuzzing the kernel may
try to do this. For SMC this means a socket refcounting problem.
This patch makes sure a shutdown call for an SMC socket in state
SMC_LISTEN simply returns with -ENOTCONN.
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The wait_address argument is always directly derived from the filp
argument, so remove it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Remember the fallback reason code and the peer diagnosis code for
smc sockets, and provide them in smc_diag.c to the netlink interface.
And add more detailed reason codes.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
SMC code uses the base gid for VLAN traffic. The gids exchanged in
the CLC handshake and the gid index used for the QP have to switch
from the base gid to the appropriate vlan gid.
When searching for a matching IB device port for a certain vlan
device, it does not make sense to return an IB device port, which
is not enabled for the used vlan_id. Add another check whether a
vlan gid exists for a certain IB device port.
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Link confirmation will always be sent across the new link being
confirmed. This allows to shrink the parameter list.
No functional change.
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The functions to read and write cursors are exclusively used to copy
cursors. Therefore switch to a respective function instead.
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking fixes from David Miller:
"Lots of fixes, here goes:
1) NULL deref in qtnfmac, from Gustavo A. R. Silva.
2) Kernel oops when fw download fails in rtlwifi, from Ping-Ke Shih.
3) Lost completion messages in AF_XDP, from Magnus Karlsson.
4) Correct bogus self-assignment in rhashtable, from Rishabh
Bhatnagar.
5) Fix regression in ipv6 route append handling, from David Ahern.
6) Fix masking in __set_phy_supported(), from Heiner Kallweit.
7) Missing module owner set in x_tables icmp, from Florian Westphal.
8) liquidio's timeouts are HZ dependent, fix from Nicholas Mc Guire.
9) Link setting fixes for sh_eth and ravb, from Vladimir Zapolskiy.
10) Fix NULL deref when using chains in act_csum, from Davide Caratti.
11) XDP_REDIRECT needs to check if the interface is up and whether the
MTU is sufficient. From Toshiaki Makita.
12) Net diag can do a double free when killing TCP_NEW_SYN_RECV
connections, from Lorenzo Colitti.
13) nf_defrag in ipv6 can unnecessarily hold onto dst entries for a
full minute, delaying device unregister. From Eric Dumazet.
14) Update MAC entries in the correct order in ixgbe, from Alexander
Duyck.
15) Don't leave partial mangles bpf program in jit_subprogs, from
Daniel Borkmann.
16) Fix pfmemalloc SKB state propagation, from Stefano Brivio.
17) Fix ACK handling in DCTCP congestion control, from Yuchung Cheng.
18) Use after free in tun XDP_TX, from Toshiaki Makita.
19) Stale ipv6 header pointer in ipv6 gre code, from Prashant Bhole.
20) Don't reuse remainder of RX page when XDP is set in mlx4, from
Saeed Mahameed.
21) Fix window probe handling of TCP rapair sockets, from Stefan
Baranoff.
22) Missing socket locking in smc_ioctl(), from Ursula Braun.
23) IPV6_ILA needs DST_CACHE, from Arnd Bergmann.
24) Spectre v1 fix in cxgb3, from Gustavo A. R. Silva.
25) Two spots in ipv6 do a rol32() on a hash value but ignore the
result. Fixes from Colin Ian King"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (176 commits)
tcp: identify cryptic messages as TCP seq # bugs
ptp: fix missing break in switch
hv_netvsc: Fix napi reschedule while receive completion is busy
MAINTAINERS: Drop inactive Vitaly Bordug's email
net: cavium: Add fine-granular dependencies on PCI
net: qca_spi: Fix log level if probe fails
net: qca_spi: Make sure the QCA7000 reset is triggered
net: qca_spi: Avoid packet drop during initial sync
ipv6: fix useless rol32 call on hash
ipv6: sr: fix useless rol32 call on hash
net: sched: Using NULL instead of plain integer
net: usb: asix: replace mii_nway_restart in resume path
net: cxgb3_main: fix potential Spectre v1
lib/rhashtable: consider param->min_size when setting initial table size
net/smc: reset recv timeout after clc handshake
net/smc: add error handling for get_user()
net/smc: optimize consumer cursor updates
net/nfc: Avoid stalls when nfc_alloc_send_skb() returned NULL.
ipv6: ila: select CONFIG_DST_CACHE
net: usb: rtl8150: demote allmulti message to dev_dbg()
...
For security reasons the return code of get_user() should always be
checked.
Fixes: 01d2f7e2cd ("net/smc: sockopts TCP_NODELAY and TCP_CORK")
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
SMC ioctl processing requires the sock lock to work properly in
all thinkable scenarios.
Problem has been found with RaceFuzzer and fixes:
KASAN: null-ptr-deref Read in smc_ioctl
Reported-by: Byoungyoung Lee <lifeasageek@gmail.com>
Reported-by: syzbot+35b2c5aa76fd398b9fd4@syzkaller.appspotmail.com
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
smc_release() calls a sock_put() for smc fallback sockets to cover
the passive closing sock_hold() in __smc_connect() and
smc_tcp_listen_work(). This does not make sense for sockets in state
SMC_LISTEN and SMC_INIT.
An SMC socket stays in state SMC_INIT if connect fails. The sock_put
in smc_connect_abort() does not cover all failures. Move it into
smc_connect_decline_fallback().
Fixes: ee9dfbef02 ("net/smc: handle sockopts forcing fallback")
Reported-by: syzbot+3a0748c8f2f210c0ef9b@syzkaller.appspotmail.com
Reported-by: syzbot+9e60d2428a42049a592a@syzkaller.appspotmail.com
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
My networking merge (commit 4e33d7d479: "Pull networking fixes from
David Miller") got the poll() handling conflict wrong for af_smc.
The conflict between my a11e1d432b ("Revert changes to convert to
->poll_mask() and aio IOCB_CMD_POLL") and Ursula Braun's 24ac3a08e6
("net/smc: rebuild nonblocking connect") should have left the call to
sock_poll_wait() in place, just without the socket lock release/retake.
And I really should have realized that. But happily, I at least asked
Ursula to double-check the merge, and she set me right.
This also fixes an incidental whitespace issue nearby that annoyed me
while looking at this.
Pointed-out-by: Ursula Braun <ubraun@linux.ibm.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Simple overlapping changes in stmmac driver.
Adjust skb_gro_flush_final_remcsum function signature to make GRO list
changes in net-next, as per Stephen Rothwell's example merge
resolution.
Signed-off-by: David S. Miller <davem@davemloft.net>
