<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/net/rds, branch v4.7-rc2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net</title>
<updated>2016-05-21T03:01:26+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-05-21T03:01:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=087afe8aaf562dc7a53f2577049830d6a3245742'/>
<id>087afe8aaf562dc7a53f2577049830d6a3245742</id>
<content type='text'>
Pull networking fixes and more updates from David Miller:

 1) Tunneling fixes from Tom Herbert and Alexander Duyck.

 2) AF_UNIX updates some struct sock bit fields with the socket lock,
    whereas setsockopt() sets overlapping ones with locking.  Seperate
    out the synchronized vs.  the AF_UNIX unsynchronized ones to avoid
    corruption.  From Andrey Ryabinin.

 3) Mount BPF filesystem with mount_nodev rather than mount_ns, from
    Eric Biederman.

 4) A couple kmemdup conversions, from Muhammad Falak R Wani.

 5) BPF verifier fixes from Alexei Starovoitov.

 6) Don't let tunneled UDP packets get stuck in socket queues, if
    something goes wrong during the encapsulation just drop the packet
    rather than signalling an error up the call stack.  From Hannes
    Frederic Sowa.

 7) SKB ref after free in batman-adv, from Florian Westphal.

 8) TCP iSCSI, ocfs2, rds, and tipc have to disable BH in it's TCP
    callbacks since the TCP stack runs pre-emptibly now.  From Eric
    Dumazet.

 9) Fix crash in fixed_phy_add, from Rabin Vincent.

10) Fix length checks in xen-netback, from Paul Durrant.

11) Fix mixup in KEY vs KEYID macsec attributes, from Sabrina Dubroca.

12) RDS connection spamming bug fixes from Sowmini Varadhan

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (152 commits)
  net: suppress warnings on dev_alloc_skb
  uapi glibc compat: fix compilation when !__USE_MISC in glibc
  udp: prevent skbs lingering in tunnel socket queues
  bpf: teach verifier to recognize imm += ptr pattern
  bpf: support decreasing order in direct packet access
  net: usb: ch9200: use kmemdup
  ps3_gelic: use kmemdup
  net:liquidio: use kmemdup
  bpf: Use mount_nodev not mount_ns to mount the bpf filesystem
  net: cdc_ncm: update datagram size after changing mtu
  tuntap: correctly wake up process during uninit
  intel: Add support for IPv6 IP-in-IP offload
  ip6_gre: Do not allow segmentation offloads GRE_CSUM is enabled with FOU/GUE
  RDS: TCP: Avoid rds connection churn from rogue SYNs
  RDS: TCP: rds_tcp_accept_worker() must exit gracefully when terminating rds-tcp
  net: sock: move -&gt;sk_shutdown out of bitfields.
  ipv6: Don't reset inner headers in ip6_tnl_xmit
  ip4ip6: Support for GSO/GRO
  ip6ip6: Support for GSO/GRO
  ipv6: Set features for IPv6 tunnels
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking fixes and more updates from David Miller:

 1) Tunneling fixes from Tom Herbert and Alexander Duyck.

 2) AF_UNIX updates some struct sock bit fields with the socket lock,
    whereas setsockopt() sets overlapping ones with locking.  Seperate
    out the synchronized vs.  the AF_UNIX unsynchronized ones to avoid
    corruption.  From Andrey Ryabinin.

 3) Mount BPF filesystem with mount_nodev rather than mount_ns, from
    Eric Biederman.

 4) A couple kmemdup conversions, from Muhammad Falak R Wani.

 5) BPF verifier fixes from Alexei Starovoitov.

 6) Don't let tunneled UDP packets get stuck in socket queues, if
    something goes wrong during the encapsulation just drop the packet
    rather than signalling an error up the call stack.  From Hannes
    Frederic Sowa.

 7) SKB ref after free in batman-adv, from Florian Westphal.

 8) TCP iSCSI, ocfs2, rds, and tipc have to disable BH in it's TCP
    callbacks since the TCP stack runs pre-emptibly now.  From Eric
    Dumazet.

 9) Fix crash in fixed_phy_add, from Rabin Vincent.

10) Fix length checks in xen-netback, from Paul Durrant.

11) Fix mixup in KEY vs KEYID macsec attributes, from Sabrina Dubroca.

12) RDS connection spamming bug fixes from Sowmini Varadhan

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (152 commits)
  net: suppress warnings on dev_alloc_skb
  uapi glibc compat: fix compilation when !__USE_MISC in glibc
  udp: prevent skbs lingering in tunnel socket queues
  bpf: teach verifier to recognize imm += ptr pattern
  bpf: support decreasing order in direct packet access
  net: usb: ch9200: use kmemdup
  ps3_gelic: use kmemdup
  net:liquidio: use kmemdup
  bpf: Use mount_nodev not mount_ns to mount the bpf filesystem
  net: cdc_ncm: update datagram size after changing mtu
  tuntap: correctly wake up process during uninit
  intel: Add support for IPv6 IP-in-IP offload
  ip6_gre: Do not allow segmentation offloads GRE_CSUM is enabled with FOU/GUE
  RDS: TCP: Avoid rds connection churn from rogue SYNs
  RDS: TCP: rds_tcp_accept_worker() must exit gracefully when terminating rds-tcp
  net: sock: move -&gt;sk_shutdown out of bitfields.
  ipv6: Don't reset inner headers in ip6_tnl_xmit
  ip4ip6: Support for GSO/GRO
  ip6ip6: Support for GSO/GRO
  ipv6: Set features for IPv6 tunnels
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>RDS: TCP: Avoid rds connection churn from rogue SYNs</title>
<updated>2016-05-20T23:19:57+00:00</updated>
<author>
<name>Sowmini Varadhan</name>
<email>sowmini.varadhan@oracle.com</email>
</author>
<published>2016-05-18T17:06:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c948bb5c2cc4d63f9d76fc02baf5a8331e3cd27f'/>
<id>c948bb5c2cc4d63f9d76fc02baf5a8331e3cd27f</id>
<content type='text'>
When a rogue SYN is received after the connection arbitration
algorithm has converged, the incoming SYN should not needlessly
quiesce the transmit path, and it should not result in needless
TCP connection resets due to re-execution of the connection
arbitration logic.

Signed-off-by: Sowmini Varadhan &lt;sowmini.varadhan@oracle.com&gt;
Acked-by: Santosh Shilimkar &lt;santosh.shilimkar@oracle.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When a rogue SYN is received after the connection arbitration
algorithm has converged, the incoming SYN should not needlessly
quiesce the transmit path, and it should not result in needless
TCP connection resets due to re-execution of the connection
arbitration logic.

Signed-off-by: Sowmini Varadhan &lt;sowmini.varadhan@oracle.com&gt;
Acked-by: Santosh Shilimkar &lt;santosh.shilimkar@oracle.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>RDS: TCP: rds_tcp_accept_worker() must exit gracefully when terminating rds-tcp</title>
<updated>2016-05-20T23:19:57+00:00</updated>
<author>
<name>Sowmini Varadhan</name>
<email>sowmini.varadhan@oracle.com</email>
</author>
<published>2016-05-18T17:06:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=37e14f4fe2991f6089a9c8a3830e3ab634ec7190'/>
<id>37e14f4fe2991f6089a9c8a3830e3ab634ec7190</id>
<content type='text'>
There are two instances where we want to terminate RDS-TCP: when
exiting the netns or during module unload. In either case, the
termination sequence is to stop the listen socket, mark the
rtn-&gt;rds_tcp_listen_sock as null, and flush any accept workqs.
Thus any workqs that get flushed at this point will encounter a
null rds_tcp_listen_sock, and must exit gracefully to allow
the RDS-TCP termination to complete successfully.

Signed-off-by: Sowmini Varadhan &lt;sowmini.varadhan@oracle.com&gt;
Acked-by: Santosh Shilimkar &lt;santosh.shilimkar@oracle.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There are two instances where we want to terminate RDS-TCP: when
exiting the netns or during module unload. In either case, the
termination sequence is to stop the listen socket, mark the
rtn-&gt;rds_tcp_listen_sock as null, and flush any accept workqs.
Thus any workqs that get flushed at this point will encounter a
null rds_tcp_listen_sock, and must exit gracefully to allow
the RDS-TCP termination to complete successfully.

Signed-off-by: Sowmini Varadhan &lt;sowmini.varadhan@oracle.com&gt;
Acked-by: Santosh Shilimkar &lt;santosh.shilimkar@oracle.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma</title>
<updated>2016-05-20T21:35:07+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-05-20T21:35:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=76b584d3125a1f7d8b64e9c522a4555bc2844bde'/>
<id>76b584d3125a1f7d8b64e9c522a4555bc2844bde</id>
<content type='text'>
Pull rdma updates from Doug Ledford:
 "Primary 4.7 merge window changes

   - Updates to the new Intel X722 iWARP driver
   - Updates to the hfi1 driver
   - Fixes for the iw_cxgb4 driver
   - Misc core fixes
   - Generic RDMA READ/WRITE API addition
   - SRP updates
   - Misc ipoib updates
   - Minor mlx5 updates"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (148 commits)
  IB/mlx5: Fire the CQ completion handler from tasklet
  net/mlx5_core: Use tasklet for user-space CQ completion events
  IB/core: Do not require CAP_NET_ADMIN for packet sniffing
  IB/mlx4: Fix unaligned access in send_reply_to_slave
  IB/mlx5: Report Scatter FCS device capability when supported
  IB/mlx5: Add Scatter FCS support for Raw Packet QP
  IB/core: Add Scatter FCS create flag
  IB/core: Add Raw Scatter FCS device capability
  IB/core: Add extended device capability flags
  i40iw: pass hw_stats by reference rather than by value
  i40iw: Remove unnecessary synchronize_irq() before free_irq()
  i40iw: constify i40iw_vf_cqp_ops structure
  IB/mlx5: Add UARs write-combining and non-cached mapping
  IB/mlx5: Allow mapping the free running counter on PROT_EXEC
  IB/mlx4: Use list_for_each_entry_safe
  IB/SA: Use correct free function
  IB/core: Fix a potential array overrun in CMA and SA agent
  IB/core: Remove unnecessary check in ibnl_rcv_msg
  IB/IWPM: Fix a potential skb leak
  RDMA/nes: replace custom print_hex_dump()
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull rdma updates from Doug Ledford:
 "Primary 4.7 merge window changes

   - Updates to the new Intel X722 iWARP driver
   - Updates to the hfi1 driver
   - Fixes for the iw_cxgb4 driver
   - Misc core fixes
   - Generic RDMA READ/WRITE API addition
   - SRP updates
   - Misc ipoib updates
   - Minor mlx5 updates"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (148 commits)
  IB/mlx5: Fire the CQ completion handler from tasklet
  net/mlx5_core: Use tasklet for user-space CQ completion events
  IB/core: Do not require CAP_NET_ADMIN for packet sniffing
  IB/mlx4: Fix unaligned access in send_reply_to_slave
  IB/mlx5: Report Scatter FCS device capability when supported
  IB/mlx5: Add Scatter FCS support for Raw Packet QP
  IB/core: Add Scatter FCS create flag
  IB/core: Add Raw Scatter FCS device capability
  IB/core: Add extended device capability flags
  i40iw: pass hw_stats by reference rather than by value
  i40iw: Remove unnecessary synchronize_irq() before free_irq()
  i40iw: constify i40iw_vf_cqp_ops structure
  IB/mlx5: Add UARs write-combining and non-cached mapping
  IB/mlx5: Allow mapping the free running counter on PROT_EXEC
  IB/mlx4: Use list_for_each_entry_safe
  IB/SA: Use correct free function
  IB/core: Fix a potential array overrun in CMA and SA agent
  IB/core: Remove unnecessary check in ibnl_rcv_msg
  IB/IWPM: Fix a potential skb leak
  RDMA/nes: replace custom print_hex_dump()
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>rds: tcp: block BH in TCP callbacks</title>
<updated>2016-05-19T18:36:49+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2016-05-18T00:44:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=38036629cded6b96a9f9689758a88d067c4d4d44'/>
<id>38036629cded6b96a9f9689758a88d067c4d4d44</id>
<content type='text'>
TCP stack can now run from process context.

Use read_lock_bh(&amp;sk-&gt;sk_callback_lock) variant to restore previous
assumption.

Fixes: 5413d1babe8f ("net: do not block BH while processing socket backlog")
Fixes: d41a69f1d390 ("tcp: make tcp_sendmsg() aware of socket backlog")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
TCP stack can now run from process context.

Use read_lock_bh(&amp;sk-&gt;sk_callback_lock) variant to restore previous
assumption.

Fixes: 5413d1babe8f ("net: do not block BH while processing socket backlog")
Fixes: d41a69f1d390 ("tcp: make tcp_sendmsg() aware of socket backlog")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>IB/core: Add passing an offset into the SG to ib_map_mr_sg</title>
<updated>2016-05-13T17:37:11+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2016-05-03T16:01:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ff2ba9936591a1364ae21adf18366dca7608395a'/>
<id>ff2ba9936591a1364ae21adf18366dca7608395a</id>
<content type='text'>
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Tested-by: Steve Wise &lt;swise@opengridcomputing.com&gt;
Reviewed-by: Bart Van Assche &lt;bart.vanassche@sandisk.com&gt;
Reviewed-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Reviewed-by: Steve Wise &lt;swise@opengridcomputing.com&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Tested-by: Steve Wise &lt;swise@opengridcomputing.com&gt;
Reviewed-by: Bart Van Assche &lt;bart.vanassche@sandisk.com&gt;
Reviewed-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Reviewed-by: Steve Wise &lt;swise@opengridcomputing.com&gt;
Signed-off-by: Doug Ledford &lt;dledford@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net</title>
<updated>2016-05-04T04:52:29+00:00</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2016-05-04T04:52:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=cba653210056cf47cc1969f831f05ddfb99ee2bd'/>
<id>cba653210056cf47cc1969f831f05ddfb99ee2bd</id>
<content type='text'>
Conflicts:
	net/ipv4/ip_gre.c

Minor conflicts between tunnel bug fixes in net and
ipv6 tunnel cleanups in net-next.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Conflicts:
	net/ipv4/ip_gre.c

Minor conflicts between tunnel bug fixes in net and
ipv6 tunnel cleanups in net-next.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>RDS: TCP: Synchronize accept() and connect() paths on t_conn_lock.</title>
<updated>2016-05-03T20:03:44+00:00</updated>
<author>
<name>Sowmini Varadhan</name>
<email>sowmini.varadhan@oracle.com</email>
</author>
<published>2016-05-02T18:24:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=bd7c5f983f3185b75cc23bdd5dbc3a676aef3d1e'/>
<id>bd7c5f983f3185b75cc23bdd5dbc3a676aef3d1e</id>
<content type='text'>
An arbitration scheme for duelling SYNs is implemented as part of
commit 241b271952eb ("RDS-TCP: Reset tcp callbacks if re-using an
outgoing socket in rds_tcp_accept_one()") which ensures that both nodes
involved will arrive at the same arbitration decision. However, this
needs to be synchronized with an outgoing SYN to be generated by
rds_tcp_conn_connect(). This commit achieves the synchronization
through the t_conn_lock mutex in struct rds_tcp_connection.

The rds_conn_state is checked in rds_tcp_conn_connect() after acquiring
the t_conn_lock mutex.  A SYN is sent out only if the RDS connection is
not already UP (an UP would indicate that rds_tcp_accept_one() has
completed 3WH, so no SYN needs to be generated).

Similarly, the rds_conn_state is checked in rds_tcp_accept_one() after
acquiring the t_conn_lock mutex. The only acceptable states (to
allow continuation of the arbitration logic) are UP (i.e., outgoing SYN
was SYN-ACKed by peer after it sent us the SYN) or CONNECTING (we sent
outgoing SYN before we saw incoming SYN).

Signed-off-by: Sowmini Varadhan &lt;sowmini.varadhan@oracle.com&gt;
Acked-by: Santosh Shilimkar &lt;santosh.shilimkar@oracle.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
An arbitration scheme for duelling SYNs is implemented as part of
commit 241b271952eb ("RDS-TCP: Reset tcp callbacks if re-using an
outgoing socket in rds_tcp_accept_one()") which ensures that both nodes
involved will arrive at the same arbitration decision. However, this
needs to be synchronized with an outgoing SYN to be generated by
rds_tcp_conn_connect(). This commit achieves the synchronization
through the t_conn_lock mutex in struct rds_tcp_connection.

The rds_conn_state is checked in rds_tcp_conn_connect() after acquiring
the t_conn_lock mutex.  A SYN is sent out only if the RDS connection is
not already UP (an UP would indicate that rds_tcp_accept_one() has
completed 3WH, so no SYN needs to be generated).

Similarly, the rds_conn_state is checked in rds_tcp_accept_one() after
acquiring the t_conn_lock mutex. The only acceptable states (to
allow continuation of the arbitration logic) are UP (i.e., outgoing SYN
was SYN-ACKed by peer after it sent us the SYN) or CONNECTING (we sent
outgoing SYN before we saw incoming SYN).

Signed-off-by: Sowmini Varadhan &lt;sowmini.varadhan@oracle.com&gt;
Acked-by: Santosh Shilimkar &lt;santosh.shilimkar@oracle.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>RDS:TCP: Synchronize rds_tcp_accept_one with rds_send_xmit when resetting t_sock</title>
<updated>2016-05-03T20:03:44+00:00</updated>
<author>
<name>Sowmini Varadhan</name>
<email>sowmini.varadhan@oracle.com</email>
</author>
<published>2016-05-02T18:24:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=eb192840266fab3e3da644018121eed30153355d'/>
<id>eb192840266fab3e3da644018121eed30153355d</id>
<content type='text'>
There is a race condition between rds_send_xmit -&gt; rds_tcp_xmit
and the code that deals with resolution of duelling syns added
by commit 241b271952eb ("RDS-TCP: Reset tcp callbacks if re-using an
outgoing socket in rds_tcp_accept_one()").

Specifically, we may end up derefencing a null pointer in rds_send_xmit
if we have the interleaving sequence:
           rds_tcp_accept_one                  rds_send_xmit

                                             conn is RDS_CONN_UP, so
    					 invoke rds_tcp_xmit

                                             tc = conn-&gt;c_transport_data
        rds_tcp_restore_callbacks
            /* reset t_sock */
    					 null ptr deref from tc-&gt;t_sock

The race condition can be avoided without adding the overhead of
additional locking in the xmit path: have rds_tcp_accept_one wait
for rds_tcp_xmit threads to complete before resetting callbacks.
The synchronization can be done in the same manner as rds_conn_shutdown().
First set the rds_conn_state to something other than RDS_CONN_UP
(so that new threads cannot get into rds_tcp_xmit()), then wait for
RDS_IN_XMIT to be cleared in the conn-&gt;c_flags indicating that any
threads in rds_tcp_xmit are done.

Fixes: 241b271952eb ("RDS-TCP: Reset tcp callbacks if re-using an
outgoing socket in rds_tcp_accept_one()")
Signed-off-by: Sowmini Varadhan &lt;sowmini.varadhan@oracle.com&gt;
Acked-by: Santosh Shilimkar &lt;santosh.shilimkar@oracle.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There is a race condition between rds_send_xmit -&gt; rds_tcp_xmit
and the code that deals with resolution of duelling syns added
by commit 241b271952eb ("RDS-TCP: Reset tcp callbacks if re-using an
outgoing socket in rds_tcp_accept_one()").

Specifically, we may end up derefencing a null pointer in rds_send_xmit
if we have the interleaving sequence:
           rds_tcp_accept_one                  rds_send_xmit

                                             conn is RDS_CONN_UP, so
    					 invoke rds_tcp_xmit

                                             tc = conn-&gt;c_transport_data
        rds_tcp_restore_callbacks
            /* reset t_sock */
    					 null ptr deref from tc-&gt;t_sock

The race condition can be avoided without adding the overhead of
additional locking in the xmit path: have rds_tcp_accept_one wait
for rds_tcp_xmit threads to complete before resetting callbacks.
The synchronization can be done in the same manner as rds_conn_shutdown().
First set the rds_conn_state to something other than RDS_CONN_UP
(so that new threads cannot get into rds_tcp_xmit()), then wait for
RDS_IN_XMIT to be cleared in the conn-&gt;c_flags indicating that any
threads in rds_tcp_xmit are done.

Fixes: 241b271952eb ("RDS-TCP: Reset tcp callbacks if re-using an
outgoing socket in rds_tcp_accept_one()")
Signed-off-by: Sowmini Varadhan &lt;sowmini.varadhan@oracle.com&gt;
Acked-by: Santosh Shilimkar &lt;santosh.shilimkar@oracle.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>RDS: TCP: Call pskb_extract() helper function</title>
<updated>2016-04-25T20:54:14+00:00</updated>
<author>
<name>Sowmini Varadhan</name>
<email>sowmini.varadhan@oracle.com</email>
</author>
<published>2016-04-23T01:36:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=947d2756cddec83c72af99b02010002ddc57aeb3'/>
<id>947d2756cddec83c72af99b02010002ddc57aeb3</id>
<content type='text'>
rds-stress experiments with request size 256 bytes, 8K acks,
using 16 threads show a 40% improvment when pskb_extract()
replaces the {skb_clone(..); pskb_pull(..); pskb_trim(..);}
pattern in the Rx path, so we leverage the perf gain with
this commit.

Signed-off-by: Sowmini Varadhan &lt;sowmini.varadhan@oracle.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
rds-stress experiments with request size 256 bytes, 8K acks,
using 16 threads show a 40% improvment when pskb_extract()
replaces the {skb_clone(..); pskb_pull(..); pskb_trim(..);}
pattern in the Rx path, so we leverage the perf gain with
this commit.

Signed-off-by: Sowmini Varadhan &lt;sowmini.varadhan@oracle.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
</feed>
