<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/net/core/netpoll.c, branch v5.1</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-next</title>
<updated>2018-12-27T21:04:52+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-12-27T21:04:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e0c38a4d1f196a4b17d2eba36afff8f656a4f1de'/>
<id>e0c38a4d1f196a4b17d2eba36afff8f656a4f1de</id>
<content type='text'>
Pull networking updates from David Miller:

 1) New ipset extensions for matching on destination MAC addresses, from
    Stefano Brivio.

 2) Add ipv4 ttl and tos, plus ipv6 flow label and hop limit offloads to
    nfp driver. From Stefano Brivio.

 3) Implement GRO for plain UDP sockets, from Paolo Abeni.

 4) Lots of work from Michał Mirosław to eliminate the VLAN_TAG_PRESENT
    bit so that we could support the entire vlan_tci value.

 5) Rework the IPSEC policy lookups to better optimize more usecases,
    from Florian Westphal.

 6) Infrastructure changes eliminating direct manipulation of SKB lists
    wherever possible, and to always use the appropriate SKB list
    helpers. This work is still ongoing...

 7) Lots of PHY driver and state machine improvements and
    simplifications, from Heiner Kallweit.

 8) Various TSO deferral refinements, from Eric Dumazet.

 9) Add ntuple filter support to aquantia driver, from Dmitry Bogdanov.

10) Batch dropping of XDP packets in tuntap, from Jason Wang.

11) Lots of cleanups and improvements to the r8169 driver from Heiner
    Kallweit, including support for -&gt;xmit_more. This driver has been
    getting some much needed love since he started working on it.

12) Lots of new forwarding selftests from Petr Machata.

13) Enable VXLAN learning in mlxsw driver, from Ido Schimmel.

14) Packed ring support for virtio, from Tiwei Bie.

15) Add new Aquantia AQtion USB driver, from Dmitry Bezrukov.

16) Add XDP support to dpaa2-eth driver, from Ioana Ciocoi Radulescu.

17) Implement coalescing on TCP backlog queue, from Eric Dumazet.

18) Implement carrier change in tun driver, from Nicolas Dichtel.

19) Support msg_zerocopy in UDP, from Willem de Bruijn.

20) Significantly improve garbage collection of neighbor objects when
    the table has many PERMANENT entries, from David Ahern.

21) Remove egdev usage from nfp and mlx5, and remove the facility
    completely from the tree as it no longer has any users. From Oz
    Shlomo and others.

22) Add a NETDEV_PRE_CHANGEADDR so that drivers can veto the change and
    therefore abort the operation before the commit phase (which is the
    NETDEV_CHANGEADDR event). From Petr Machata.

23) Add indirect call wrappers to avoid retpoline overhead, and use them
    in the GRO code paths. From Paolo Abeni.

24) Add support for netlink FDB get operations, from Roopa Prabhu.

25) Support bloom filter in mlxsw driver, from Nir Dotan.

26) Add SKB extension infrastructure. This consolidates the handling of
    the auxiliary SKB data used by IPSEC and bridge netfilter, and is
    designed to support the needs to MPTCP which could be integrated in
    the future.

27) Lots of XDP TX optimizations in mlx5 from Tariq Toukan.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1845 commits)
  net: dccp: fix kernel crash on module load
  drivers/net: appletalk/cops: remove redundant if statement and mask
  bnx2x: Fix NULL pointer dereference in bnx2x_del_all_vlans() on some hw
  net/net_namespace: Check the return value of register_pernet_subsys()
  net/netlink_compat: Fix a missing check of nla_parse_nested
  ieee802154: lowpan_header_create check must check daddr
  net/mlx4_core: drop useless LIST_HEAD
  mlxsw: spectrum: drop useless LIST_HEAD
  net/mlx5e: drop useless LIST_HEAD
  iptunnel: Set tun_flags in the iptunnel_metadata_reply from src
  net/mlx5e: fix semicolon.cocci warnings
  staging: octeon: fix build failure with XFRM enabled
  net: Revert recent Spectre-v1 patches.
  can: af_can: Fix Spectre v1 vulnerability
  packet: validate address length if non-zero
  nfc: af_nfc: Fix Spectre v1 vulnerability
  phonet: af_phonet: Fix Spectre v1 vulnerability
  net: core: Fix Spectre v1 vulnerability
  net: minor cleanup in skb_ext_add()
  net: drop the unused helper skb_ext_get()
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking updates from David Miller:

 1) New ipset extensions for matching on destination MAC addresses, from
    Stefano Brivio.

 2) Add ipv4 ttl and tos, plus ipv6 flow label and hop limit offloads to
    nfp driver. From Stefano Brivio.

 3) Implement GRO for plain UDP sockets, from Paolo Abeni.

 4) Lots of work from Michał Mirosław to eliminate the VLAN_TAG_PRESENT
    bit so that we could support the entire vlan_tci value.

 5) Rework the IPSEC policy lookups to better optimize more usecases,
    from Florian Westphal.

 6) Infrastructure changes eliminating direct manipulation of SKB lists
    wherever possible, and to always use the appropriate SKB list
    helpers. This work is still ongoing...

 7) Lots of PHY driver and state machine improvements and
    simplifications, from Heiner Kallweit.

 8) Various TSO deferral refinements, from Eric Dumazet.

 9) Add ntuple filter support to aquantia driver, from Dmitry Bogdanov.

10) Batch dropping of XDP packets in tuntap, from Jason Wang.

11) Lots of cleanups and improvements to the r8169 driver from Heiner
    Kallweit, including support for -&gt;xmit_more. This driver has been
    getting some much needed love since he started working on it.

12) Lots of new forwarding selftests from Petr Machata.

13) Enable VXLAN learning in mlxsw driver, from Ido Schimmel.

14) Packed ring support for virtio, from Tiwei Bie.

15) Add new Aquantia AQtion USB driver, from Dmitry Bezrukov.

16) Add XDP support to dpaa2-eth driver, from Ioana Ciocoi Radulescu.

17) Implement coalescing on TCP backlog queue, from Eric Dumazet.

18) Implement carrier change in tun driver, from Nicolas Dichtel.

19) Support msg_zerocopy in UDP, from Willem de Bruijn.

20) Significantly improve garbage collection of neighbor objects when
    the table has many PERMANENT entries, from David Ahern.

21) Remove egdev usage from nfp and mlx5, and remove the facility
    completely from the tree as it no longer has any users. From Oz
    Shlomo and others.

22) Add a NETDEV_PRE_CHANGEADDR so that drivers can veto the change and
    therefore abort the operation before the commit phase (which is the
    NETDEV_CHANGEADDR event). From Petr Machata.

23) Add indirect call wrappers to avoid retpoline overhead, and use them
    in the GRO code paths. From Paolo Abeni.

24) Add support for netlink FDB get operations, from Roopa Prabhu.

25) Support bloom filter in mlxsw driver, from Nir Dotan.

26) Add SKB extension infrastructure. This consolidates the handling of
    the auxiliary SKB data used by IPSEC and bridge netfilter, and is
    designed to support the needs to MPTCP which could be integrated in
    the future.

27) Lots of XDP TX optimizations in mlx5 from Tariq Toukan.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1845 commits)
  net: dccp: fix kernel crash on module load
  drivers/net: appletalk/cops: remove redundant if statement and mask
  bnx2x: Fix NULL pointer dereference in bnx2x_del_all_vlans() on some hw
  net/net_namespace: Check the return value of register_pernet_subsys()
  net/netlink_compat: Fix a missing check of nla_parse_nested
  ieee802154: lowpan_header_create check must check daddr
  net/mlx4_core: drop useless LIST_HEAD
  mlxsw: spectrum: drop useless LIST_HEAD
  net/mlx5e: drop useless LIST_HEAD
  iptunnel: Set tun_flags in the iptunnel_metadata_reply from src
  net/mlx5e: fix semicolon.cocci warnings
  staging: octeon: fix build failure with XFRM enabled
  net: Revert recent Spectre-v1 patches.
  can: af_can: Fix Spectre v1 vulnerability
  packet: validate address length if non-zero
  nfc: af_nfc: Fix Spectre v1 vulnerability
  phonet: af_phonet: Fix Spectre v1 vulnerability
  net: core: Fix Spectre v1 vulnerability
  net: minor cleanup in skb_ext_add()
  net: drop the unused helper skb_ext_get()
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>net: core: dev: Add extack argument to dev_open()</title>
<updated>2018-12-06T21:26:06+00:00</updated>
<author>
<name>Petr Machata</name>
<email>petrm@mellanox.com</email>
</author>
<published>2018-12-06T17:05:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=00f54e68924eaf075f3f24be18557899d347bc4a'/>
<id>00f54e68924eaf075f3f24be18557899d347bc4a</id>
<content type='text'>
In order to pass extack together with NETDEV_PRE_UP notifications, it's
necessary to route the extack to __dev_open() from diverse (possibly
indirect) callers. One prominent API through which the notification is
invoked is dev_open().

Therefore extend dev_open() with and extra extack argument and update
all users. Most of the calls end up just encoding NULL, but bond and
team drivers have the extack readily available.

Signed-off-by: Petr Machata &lt;petrm@mellanox.com&gt;
Acked-by: Jiri Pirko &lt;jiri@mellanox.com&gt;
Reviewed-by: Ido Schimmel &lt;idosch@mellanox.com&gt;
Reviewed-by: David Ahern &lt;dsahern@gmail.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>
In order to pass extack together with NETDEV_PRE_UP notifications, it's
necessary to route the extack to __dev_open() from diverse (possibly
indirect) callers. One prominent API through which the notification is
invoked is dev_open().

Therefore extend dev_open() with and extra extack argument and update
all users. Most of the calls end up just encoding NULL, but bond and
team drivers have the extack readily available.

Signed-off-by: Petr Machata &lt;petrm@mellanox.com&gt;
Acked-by: Jiri Pirko &lt;jiri@mellanox.com&gt;
Reviewed-by: Ido Schimmel &lt;idosch@mellanox.com&gt;
Reviewed-by: David Ahern &lt;dsahern@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu</title>
<updated>2018-12-04T06:52:30+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2018-12-04T06:52:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4bbfd7467cfc7d42e18d3008fa6a28ffd56e901a'/>
<id>4bbfd7467cfc7d42e18d3008fa6a28ffd56e901a</id>
<content type='text'>
Pull RCU changes from Paul E. McKenney:

- Convert RCU's BUG_ON() and similar calls to WARN_ON() and similar.

- Replace calls of RCU-bh and RCU-sched update-side functions
  to their vanilla RCU counterparts.  This series is a step
  towards complete removal of the RCU-bh and RCU-sched update-side
  functions.

  ( Note that some of these conversions are going upstream via their
    respective maintainers. )

- Documentation updates, including a number of flavor-consolidation
  updates from Joel Fernandes.

- Miscellaneous fixes.

- Automate generation of the initrd filesystem used for
  rcutorture testing.

- Convert spin_is_locked() assertions to instead use lockdep.

  ( Note that some of these conversions are going upstream via their
    respective maintainers. )

- SRCU updates, especially including a fix from Dennis Krein
  for a bag-on-head-class bug.

- RCU torture-test updates.

Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull RCU changes from Paul E. McKenney:

- Convert RCU's BUG_ON() and similar calls to WARN_ON() and similar.

- Replace calls of RCU-bh and RCU-sched update-side functions
  to their vanilla RCU counterparts.  This series is a step
  towards complete removal of the RCU-bh and RCU-sched update-side
  functions.

  ( Note that some of these conversions are going upstream via their
    respective maintainers. )

- Documentation updates, including a number of flavor-consolidation
  updates from Joel Fernandes.

- Miscellaneous fixes.

- Automate generation of the initrd filesystem used for
  rcutorture testing.

- Convert spin_is_locked() assertions to instead use lockdep.

  ( Note that some of these conversions are going upstream via their
    respective maintainers. )

- SRCU updates, especially including a fix from Dennis Krein
  for a bag-on-head-class bug.

- RCU torture-test updates.

Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net/core: Replace call_rcu_bh() and synchronize_rcu_bh()</title>
<updated>2018-12-01T20:38:47+00:00</updated>
<author>
<name>Paul E. McKenney</name>
<email>paulmck@linux.ibm.com</email>
</author>
<published>2018-11-07T03:43:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5da54c1810e52f7abba0ff7932dddd761f945875'/>
<id>5da54c1810e52f7abba0ff7932dddd761f945875</id>
<content type='text'>
Now that call_rcu()'s callback is not invoked until after all bh-disable
regions of code have completed (in addition to explicitly marked
RCU read-side critical sections), call_rcu() can be used in place of
call_rcu_bh().  Similarly, synchronize_rcu() can be used in place of
synchronize_rcu_bh().  This commit therefore makes these changes.

Signed-off-by: Paul E. McKenney &lt;paulmck@linux.ibm.com&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: &lt;netdev@vger.kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Now that call_rcu()'s callback is not invoked until after all bh-disable
regions of code have completed (in addition to explicitly marked
RCU read-side critical sections), call_rcu() can be used in place of
call_rcu_bh().  Similarly, synchronize_rcu() can be used in place of
synchronize_rcu_bh().  This commit therefore makes these changes.

Signed-off-by: Paul E. McKenney &lt;paulmck@linux.ibm.com&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: &lt;netdev@vger.kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: core: netpoll: Enable netconsole IPv6 link local address</title>
<updated>2018-11-06T01:07:10+00:00</updated>
<author>
<name>Matwey V. Kornilov</name>
<email>matwey@sai.msu.ru</email>
</author>
<published>2018-11-02T18:19:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d016b4a3562b745fd9fa387a47d8de62ccd7e241'/>
<id>d016b4a3562b745fd9fa387a47d8de62ccd7e241</id>
<content type='text'>
There is no reason to discard using source link local address when
remote netconsole IPv6 address is set to be link local one.

The patch allows administrators to use IPv6 netconsole without
explicitly configuring source address:

    netconsole=@/,@fe80::5054:ff:fe2f:6012/

Signed-off-by: Matwey V. Kornilov &lt;matwey@sai.msu.ru&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 no reason to discard using source link local address when
remote netconsole IPv6 address is set to be link local one.

The patch allows administrators to use IPv6 netconsole without
explicitly configuring source address:

    netconsole=@/,@fe80::5054:ff:fe2f:6012/

Signed-off-by: Matwey V. Kornilov &lt;matwey@sai.msu.ru&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netpoll: allow cleanup to be synchronous</title>
<updated>2018-10-20T00:01:43+00:00</updated>
<author>
<name>Debabrata Banerjee</name>
<email>dbanerje@akamai.com</email>
</author>
<published>2018-10-18T15:18:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c9fbd71f73094311b31ee703a918e9e0df502cef'/>
<id>c9fbd71f73094311b31ee703a918e9e0df502cef</id>
<content type='text'>
This fixes a problem introduced by:
commit 2cde6acd49da ("netpoll: Fix __netpoll_rcu_free so that it can hold the rtnl lock")

When using netconsole on a bond, __netpoll_cleanup can asynchronously
recurse multiple times, each __netpoll_free_async call can result in
more __netpoll_free_async's. This means there is now a race between
cleanup_work queues on multiple netpoll_info's on multiple devices and
the configuration of a new netpoll. For example if a netconsole is set
to enable 0, reconfigured, and enable 1 immediately, this netconsole
will likely not work.

Given the reason for __netpoll_free_async is it can be called when rtnl
is not locked, if it is locked, we should be able to execute
synchronously. It appears to be locked everywhere it's called from.

Generalize the design pattern from the teaming driver for current
callers of __netpoll_free_async.

CC: Neil Horman &lt;nhorman@tuxdriver.com&gt;
CC: "David S. Miller" &lt;davem@davemloft.net&gt;
Signed-off-by: Debabrata Banerjee &lt;dbanerje@akamai.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>
This fixes a problem introduced by:
commit 2cde6acd49da ("netpoll: Fix __netpoll_rcu_free so that it can hold the rtnl lock")

When using netconsole on a bond, __netpoll_cleanup can asynchronously
recurse multiple times, each __netpoll_free_async call can result in
more __netpoll_free_async's. This means there is now a race between
cleanup_work queues on multiple netpoll_info's on multiple devices and
the configuration of a new netpoll. For example if a netconsole is set
to enable 0, reconfigured, and enable 1 immediately, this netconsole
will likely not work.

Given the reason for __netpoll_free_async is it can be called when rtnl
is not locked, if it is locked, we should be able to execute
synchronously. It appears to be locked everywhere it's called from.

Generalize the design pattern from the teaming driver for current
callers of __netpoll_free_async.

CC: Neil Horman &lt;nhorman@tuxdriver.com&gt;
CC: "David S. Miller" &lt;davem@davemloft.net&gt;
Signed-off-by: Debabrata Banerjee &lt;dbanerje@akamai.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "bond: take rcu lock in netpoll_send_skb_on_dev"</title>
<updated>2018-10-19T17:45:08+00:00</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2018-10-19T17:45:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=48995423143a097527802e28d7add20e5a27677a'/>
<id>48995423143a097527802e28d7add20e5a27677a</id>
<content type='text'>
This reverts commit 6fe9487892b32cb1c8b8b0d552ed7222a527fe30.

It is causing more serious regressions than the RCU warning
it is fixing.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This reverts commit 6fe9487892b32cb1c8b8b0d552ed7222a527fe30.

It is causing more serious regressions than the RCU warning
it is fixing.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bond: take rcu lock in netpoll_send_skb_on_dev</title>
<updated>2018-10-02T06:25:25+00:00</updated>
<author>
<name>Dave Jones</name>
<email>davej@codemonkey.org.uk</email>
</author>
<published>2018-09-28T20:26:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6fe9487892b32cb1c8b8b0d552ed7222a527fe30'/>
<id>6fe9487892b32cb1c8b8b0d552ed7222a527fe30</id>
<content type='text'>
The bonding driver lacks the rcu lock when it calls down into
netdev_lower_get_next_private_rcu from bond_poll_controller, which
results in a trace like:

WARNING: CPU: 2 PID: 179 at net/core/dev.c:6567 netdev_lower_get_next_private_rcu+0x34/0x40
CPU: 2 PID: 179 Comm: kworker/u16:15 Not tainted 4.19.0-rc5-backup+ #1
Workqueue: bond0 bond_mii_monitor
RIP: 0010:netdev_lower_get_next_private_rcu+0x34/0x40
Code: 48 89 fb e8 fe 29 63 ff 85 c0 74 1e 48 8b 45 00 48 81 c3 c0 00 00 00 48 8b 00 48 39 d8 74 0f 48 89 45 00 48 8b 40 f8 5b 5d c3 &lt;0f&gt; 0b eb de 31 c0 eb f5 0f 1f 40 00 0f 1f 44 00 00 48 8&gt;
RSP: 0018:ffffc9000087fa68 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff880429614560 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 00000000ffffffff RDI: ffffffffa184ada0
RBP: ffffc9000087fa80 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc9000087f9f0 R11: ffff880429798040 R12: ffff8804289d5980
R13: ffffffffa1511f60 R14: 00000000000000c8 R15: 00000000ffffffff
FS:  0000000000000000(0000) GS:ffff88042f880000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4b78fce180 CR3: 000000018180f006 CR4: 00000000001606e0
Call Trace:
 bond_poll_controller+0x52/0x170
 netpoll_poll_dev+0x79/0x290
 netpoll_send_skb_on_dev+0x158/0x2c0
 netpoll_send_udp+0x2d5/0x430
 write_ext_msg+0x1e0/0x210
 console_unlock+0x3c4/0x630
 vprintk_emit+0xfa/0x2f0
 printk+0x52/0x6e
 ? __netdev_printk+0x12b/0x220
 netdev_info+0x64/0x80
 ? bond_3ad_set_carrier+0xe9/0x180
 bond_select_active_slave+0x1fc/0x310
 bond_mii_monitor+0x709/0x9b0
 process_one_work+0x221/0x5e0
 worker_thread+0x4f/0x3b0
 kthread+0x100/0x140
 ? process_one_work+0x5e0/0x5e0
 ? kthread_delayed_work_timer_fn+0x90/0x90
 ret_from_fork+0x24/0x30

We're also doing rcu dereferences a layer up in netpoll_send_skb_on_dev
before we call down into netpoll_poll_dev, so just take the lock there.

Suggested-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Signed-off-by: Dave Jones &lt;davej@codemonkey.org.uk&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>
The bonding driver lacks the rcu lock when it calls down into
netdev_lower_get_next_private_rcu from bond_poll_controller, which
results in a trace like:

WARNING: CPU: 2 PID: 179 at net/core/dev.c:6567 netdev_lower_get_next_private_rcu+0x34/0x40
CPU: 2 PID: 179 Comm: kworker/u16:15 Not tainted 4.19.0-rc5-backup+ #1
Workqueue: bond0 bond_mii_monitor
RIP: 0010:netdev_lower_get_next_private_rcu+0x34/0x40
Code: 48 89 fb e8 fe 29 63 ff 85 c0 74 1e 48 8b 45 00 48 81 c3 c0 00 00 00 48 8b 00 48 39 d8 74 0f 48 89 45 00 48 8b 40 f8 5b 5d c3 &lt;0f&gt; 0b eb de 31 c0 eb f5 0f 1f 40 00 0f 1f 44 00 00 48 8&gt;
RSP: 0018:ffffc9000087fa68 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff880429614560 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 00000000ffffffff RDI: ffffffffa184ada0
RBP: ffffc9000087fa80 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc9000087f9f0 R11: ffff880429798040 R12: ffff8804289d5980
R13: ffffffffa1511f60 R14: 00000000000000c8 R15: 00000000ffffffff
FS:  0000000000000000(0000) GS:ffff88042f880000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4b78fce180 CR3: 000000018180f006 CR4: 00000000001606e0
Call Trace:
 bond_poll_controller+0x52/0x170
 netpoll_poll_dev+0x79/0x290
 netpoll_send_skb_on_dev+0x158/0x2c0
 netpoll_send_udp+0x2d5/0x430
 write_ext_msg+0x1e0/0x210
 console_unlock+0x3c4/0x630
 vprintk_emit+0xfa/0x2f0
 printk+0x52/0x6e
 ? __netdev_printk+0x12b/0x220
 netdev_info+0x64/0x80
 ? bond_3ad_set_carrier+0xe9/0x180
 bond_select_active_slave+0x1fc/0x310
 bond_mii_monitor+0x709/0x9b0
 process_one_work+0x221/0x5e0
 worker_thread+0x4f/0x3b0
 kthread+0x100/0x140
 ? process_one_work+0x5e0/0x5e0
 ? kthread_delayed_work_timer_fn+0x90/0x90
 ret_from_fork+0x24/0x30

We're also doing rcu dereferences a layer up in netpoll_send_skb_on_dev
before we call down into netpoll_poll_dev, so just take the lock there.

Suggested-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Signed-off-by: Dave Jones &lt;davej@codemonkey.org.uk&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netpoll: do not test NAPI_STATE_SCHED in poll_one_napi()</title>
<updated>2018-09-28T18:12:28+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2018-09-27T16:31:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c24498c6827b71f80fecc9fb1b70a792053d41a9'/>
<id>c24498c6827b71f80fecc9fb1b70a792053d41a9</id>
<content type='text'>
Since we do no longer require NAPI drivers to provide
an ndo_poll_controller(), napi_schedule() has not been done
before poll_one_napi() invocation.

So testing NAPI_STATE_SCHED is likely to cause early returns.

While we are at it, remove outdated comment.

Note to future bisections : This change might surface prior
bugs in drivers. See commit 73f21c653f93 ("bnxt_en: Fix TX
timeout during netpoll.") for one occurrence.

Fixes: ac3d9dd034e5 ("netpoll: make ndo_poll_controller() optional")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Tested-by: Song Liu &lt;songliubraving@fb.com&gt;
Cc: Michael Chan &lt;michael.chan@broadcom.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>
Since we do no longer require NAPI drivers to provide
an ndo_poll_controller(), napi_schedule() has not been done
before poll_one_napi() invocation.

So testing NAPI_STATE_SCHED is likely to cause early returns.

While we are at it, remove outdated comment.

Note to future bisections : This change might surface prior
bugs in drivers. See commit 73f21c653f93 ("bnxt_en: Fix TX
timeout during netpoll.") for one occurrence.

Fixes: ac3d9dd034e5 ("netpoll: make ndo_poll_controller() optional")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Tested-by: Song Liu &lt;songliubraving@fb.com&gt;
Cc: Michael Chan &lt;michael.chan@broadcom.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netpoll: make ndo_poll_controller() optional</title>
<updated>2018-09-24T04:55:24+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2018-09-21T22:27:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ac3d9dd034e565df2c034ab2ca71f0a9f69153c1'/>
<id>ac3d9dd034e565df2c034ab2ca71f0a9f69153c1</id>
<content type='text'>
As diagnosed by Song Liu, ndo_poll_controller() can
be very dangerous on loaded hosts, since the cpu
calling ndo_poll_controller() might steal all NAPI
contexts (for all RX/TX queues of the NIC). This capture
can last for unlimited amount of time, since one
cpu is generally not able to drain all the queues under load.

It seems that all networking drivers that do use NAPI
for their TX completions, should not provide a ndo_poll_controller().

NAPI drivers have netpoll support already handled
in core networking stack, since netpoll_poll_dev()
uses poll_napi(dev) to iterate through registered
NAPI contexts for a device.

This patch allows netpoll_poll_dev() to process NAPI
contexts even for drivers not providing ndo_poll_controller(),
allowing for following patches in NAPI drivers.

Also we export netpoll_poll_dev() so that it can be called
by bonding/team drivers in following patches.

Reported-by: Song Liu &lt;songliubraving@fb.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Tested-by: Song Liu &lt;songliubraving@fb.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>
As diagnosed by Song Liu, ndo_poll_controller() can
be very dangerous on loaded hosts, since the cpu
calling ndo_poll_controller() might steal all NAPI
contexts (for all RX/TX queues of the NIC). This capture
can last for unlimited amount of time, since one
cpu is generally not able to drain all the queues under load.

It seems that all networking drivers that do use NAPI
for their TX completions, should not provide a ndo_poll_controller().

NAPI drivers have netpoll support already handled
in core networking stack, since netpoll_poll_dev()
uses poll_napi(dev) to iterate through registered
NAPI contexts for a device.

This patch allows netpoll_poll_dev() to process NAPI
contexts even for drivers not providing ndo_poll_controller(),
allowing for following patches in NAPI drivers.

Also we export netpoll_poll_dev() so that it can be called
by bonding/team drivers in following patches.

Reported-by: Song Liu &lt;songliubraving@fb.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Tested-by: Song Liu &lt;songliubraving@fb.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
</feed>
