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<title>lwn.git/include/linux/netdevice.h, branch docs-5.6</title>
<subtitle>Linux kernel documentation tree maintained by Jonathan Corbet</subtitle>
<id>http://mirrors.hust.edu.cn/git/lwn.git/atom?h=docs-5.6</id>
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<updated>2019-12-07T19:55:11+00:00</updated>
<entry>
<title>inet: protect against too small mtu values.</title>
<updated>2019-12-07T19:55:11+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2019-12-06T04:43:46+00:00</published>
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<id>urn:sha1:501a90c945103e8627406763dac418f20f3837b2</id>
<content type='text'>
syzbot was once again able to crash a host by setting a very small mtu
on loopback device.

Let's make inetdev_valid_mtu() available in include/net/ip.h,
and use it in ip_setup_cork(), so that we protect both ip_append_page()
and __ip_append_data()

Also add a READ_ONCE() when the device mtu is read.

Pairs this lockless read with one WRITE_ONCE() in __dev_set_mtu(),
even if other code paths might write over this field.

Add a big comment in include/linux/netdevice.h about dev-&gt;mtu
needing READ_ONCE()/WRITE_ONCE() annotations.

Hopefully we will add the missing ones in followup patches.

[1]

refcount_t: saturated; leaking memory.
WARNING: CPU: 0 PID: 9464 at lib/refcount.c:22 refcount_warn_saturate+0x138/0x1f0 lib/refcount.c:22
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 9464 Comm: syz-executor850 Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x3e kernel/panic.c:582
 report_bug+0x289/0x300 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 fixup_bug arch/x86/kernel/traps.c:169 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:refcount_warn_saturate+0x138/0x1f0 lib/refcount.c:22
Code: 06 31 ff 89 de e8 c8 f5 e6 fd 84 db 0f 85 6f ff ff ff e8 7b f4 e6 fd 48 c7 c7 e0 71 4f 88 c6 05 56 a6 a4 06 01 e8 c7 a8 b7 fd &lt;0f&gt; 0b e9 50 ff ff ff e8 5c f4 e6 fd 0f b6 1d 3d a6 a4 06 31 ff 89
RSP: 0018:ffff88809689f550 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815e4336 RDI: ffffed1012d13e9c
RBP: ffff88809689f560 R08: ffff88809c50a3c0 R09: fffffbfff15d31b1
R10: fffffbfff15d31b0 R11: ffffffff8ae98d87 R12: 0000000000000001
R13: 0000000000040100 R14: ffff888099041104 R15: ffff888218d96e40
 refcount_add include/linux/refcount.h:193 [inline]
 skb_set_owner_w+0x2b6/0x410 net/core/sock.c:1999
 sock_wmalloc+0xf1/0x120 net/core/sock.c:2096
 ip_append_page+0x7ef/0x1190 net/ipv4/ip_output.c:1383
 udp_sendpage+0x1c7/0x480 net/ipv4/udp.c:1276
 inet_sendpage+0xdb/0x150 net/ipv4/af_inet.c:821
 kernel_sendpage+0x92/0xf0 net/socket.c:3794
 sock_sendpage+0x8b/0xc0 net/socket.c:936
 pipe_to_sendpage+0x2da/0x3c0 fs/splice.c:458
 splice_from_pipe_feed fs/splice.c:512 [inline]
 __splice_from_pipe+0x3ee/0x7c0 fs/splice.c:636
 splice_from_pipe+0x108/0x170 fs/splice.c:671
 generic_splice_sendpage+0x3c/0x50 fs/splice.c:842
 do_splice_from fs/splice.c:861 [inline]
 direct_splice_actor+0x123/0x190 fs/splice.c:1035
 splice_direct_to_actor+0x3b4/0xa30 fs/splice.c:990
 do_splice_direct+0x1da/0x2a0 fs/splice.c:1078
 do_sendfile+0x597/0xd00 fs/read_write.c:1464
 __do_sys_sendfile64 fs/read_write.c:1525 [inline]
 __se_sys_sendfile64 fs/read_write.c:1511 [inline]
 __x64_sys_sendfile64+0x1dd/0x220 fs/read_write.c:1511
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x441409
Code: e8 ac e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 &lt;48&gt; 3d 01 f0 ff ff 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fffb64c4f78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441409
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000005
RBP: 0000000000073b8a R08: 0000000000000010 R09: 0000000000000010
R10: 0000000000010001 R11: 0000000000000246 R12: 0000000000402180
R13: 0000000000402210 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..

Fixes: 1470ddf7f8ce ("inet: Remove explicit write references to sk/inet in ip_append_data")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma</title>
<updated>2019-11-27T18:17:28+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-11-27T18:17:28+00:00</published>
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<id>urn:sha1:d76886972823ce456c0c61cd2284e85668e2131e</id>
<content type='text'>
Pull rdma updates from Jason Gunthorpe:
 "Again another fairly quiet cycle with few notable core code changes
  and the usual variety of driver bug fixes and small improvements.

   - Various driver updates and bug fixes for siw, bnxt_re, hns, qedr,
     iw_cxgb4, vmw_pvrdma, mlx5

   - Improvements in SRPT from working with iWarp

   - SRIOV VF support for bnxt_re

   - Skeleton kernel-doc files for drivers/infiniband

   - User visible counters for events related to ODP

   - Common code for tracking of mmap lifetimes so that drivers can link
     HW object liftime to a VMA

   - ODP bug fixes and rework

   - RDMA READ support for efa

   - Removal of the very old cxgb3 driver"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (168 commits)
  RDMA/hns: Delete unnecessary callback functions for cq
  RDMA/hns: Rename the functions used inside creating cq
  RDMA/hns: Redefine the member of hns_roce_cq struct
  RDMA/hns: Redefine interfaces used in creating cq
  RDMA/efa: Expose RDMA read related attributes
  RDMA/efa: Support remote read access in MR registration
  RDMA/efa: Store network attributes in device attributes
  IB/hfi1: remove redundant assignment to variable ret
  RDMA/bnxt_re: Fix missing le16_to_cpu
  RDMA/bnxt_re: Fix stat push into dma buffer on gen p5 devices
  RDMA/bnxt_re: Fix chip number validation Broadcom's Gen P5 series
  RDMA/bnxt_re: Fix Kconfig indentation
  IB/mlx5: Implement callbacks for getting VFs GUID attributes
  IB/ipoib: Add ndo operation for getting VFs GUID attributes
  IB/core: Add interfaces to get VF node and port GUIDs
  net/core: Add support for getting VF GUIDs
  RDMA/qedr: Fix null-pointer dereference when calling rdma_user_mmap_get_offset
  RDMA/cm: Use refcount_t type for refcount variable
  IB/mlx5: Support extended number of strides for Striding RQ
  IB/mlx4: Update HW GID table while adding vlan GID
  ...
</content>
</entry>
<entry>
<title>net/core: Add support for getting VF GUIDs</title>
<updated>2019-11-22T16:16:27+00:00</updated>
<author>
<name>Danit Goldberg</name>
<email>danitg@mellanox.com</email>
</author>
<published>2019-11-06T13:30:07+00:00</published>
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<id>urn:sha1:30aad41721e087babcf27c5192474724d555936c</id>
<content type='text'>
Introduce a new ndo: ndo_get_vf_guid, to get from the net
device the port and node GUID.

New applications can choose to use this interface to show
GUIDs with iproute2 with commands such as:

- ip link show ib4
ib4: &lt;BROADCAST,MULTICAST&gt; mtu 4092 qdisc noop state DOWN mode DEFAULT group default qlen 256
link/infiniband 00:00:0a:2d:fe:80:00:00:00:00:00:00:ec:0d:9a:03:00:44:36:8d brd 00:ff:ff:ff:ff:12:40:1b:ff:ff:00:00:00:00:00:00:ff:ff:ff:ff
vf 0     link/infiniband 00:00:0a:2d:fe:80:00:00:00:00:00:00:ec:0d:9a:03:00:44:36:8d brd 00:ff:ff:ff:ff:12:40:1b:ff:ff:00:00:00:00:00:00:ff:ff:ff:ff,
spoof checking off, NODE_GUID 22:44:33:00:33:11:00:33, PORT_GUID 10:21:33:12:00:11:22:10, link-state disable, trust off, query_rss off

Signed-off-by: Danit Goldberg &lt;danitg@mellanox.com&gt;
Acked-by: David Ahern &lt;dsahern@gmail.com&gt;
Signed-off-by: Leon Romanovsky &lt;leonro@mellanox.com&gt;
</content>
</entry>
<entry>
<title>netfilter: nf_flow_table: hardware offload support</title>
<updated>2019-11-13T03:42:26+00:00</updated>
<author>
<name>Pablo Neira Ayuso</name>
<email>pablo@netfilter.org</email>
</author>
<published>2019-11-11T23:29:56+00:00</published>
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<id>urn:sha1:c29f74e0df7a02b8303bcdce93a7c0132d62577a</id>
<content type='text'>
This patch adds the dataplane hardware offload to the flowtable
infrastructure. Three new flags represent the hardware state of this
flow:

* FLOW_OFFLOAD_HW: This flow entry resides in the hardware.
* FLOW_OFFLOAD_HW_DYING: This flow entry has been scheduled to be remove
  from hardware. This might be triggered by either packet path (via TCP
  RST/FIN packet) or via aging.
* FLOW_OFFLOAD_HW_DEAD: This flow entry has been already removed from
  the hardware, the software garbage collector can remove it from the
  software flowtable.

This patch supports for:

* IPv4 only.
* Aging via FLOW_CLS_STATS, no packet and byte counter synchronization
  at this stage.

This patch also adds the action callback that specifies how to convert
the flow entry into the flow_rule object that is passed to the driver.

Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net: use u64_stats_t in struct pcpu_lstats</title>
<updated>2019-11-08T04:03:08+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2019-11-08T00:27:22+00:00</published>
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<id>urn:sha1:fd2f4737870eb866537fbbffa2b59414b9b0c0a2</id>
<content type='text'>
In order to fix the data-race found by KCSAN, we
can use the new u64_stats_t type and its accessors instead
of plain u64 fields. This will still generate optimal code
for both 32 and 64 bit platforms.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net: provide dev_lstats_add() helper</title>
<updated>2019-11-08T04:03:08+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2019-11-08T00:27:15+00:00</published>
<link rel='alternate' type='text/html' href='http://mirrors.hust.edu.cn/git/lwn.git/commit/?id=dd5382a08157756510aa8d7269c662eccde775cb'/>
<id>urn:sha1:dd5382a08157756510aa8d7269c662eccde775cb</id>
<content type='text'>
Many network drivers need it and hand-coded the same function.

In order to ease u64_stats_t adoption, it is time to factorize.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net: provide dev_lstats_read() helper</title>
<updated>2019-11-08T04:03:08+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2019-11-08T00:27:14+00:00</published>
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<id>urn:sha1:de7d5084d82794a8e83afb994fcb07f82da3cd7b</id>
<content type='text'>
Many network drivers use hand-coded implementation of the same thing,
let's factorize things so that u64_stats_t adoption is done once.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2019-11-02T20:54:56+00:00</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2019-11-02T20:12:51+00:00</published>
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<id>urn:sha1:d31e95585ca697fb31440c6fe30113adc85ecfbd</id>
<content type='text'>
The only slightly tricky merge conflict was the netdevsim because the
mutex locking fix overlapped a lot of driver reload reorganization.

The rest were (relatively) trivial in nature.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net: remove unnecessary variables and callback</title>
<updated>2019-10-24T21:53:49+00:00</updated>
<author>
<name>Taehee Yoo</name>
<email>ap420073@gmail.com</email>
</author>
<published>2019-10-21T18:47:58+00:00</published>
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<id>urn:sha1:f3b0a18bb6cb07a9abb75e21b1f08eeaefa78e81</id>
<content type='text'>
This patch removes variables and callback these are related to the nested
device structure.
devices that can be nested have their own nest_level variable that
represents the depth of nested devices.
In the previous patch, new {lower/upper}_level variables are added and
they replace old private nest_level variable.
So, this patch removes all 'nest_level' variables.

In order to avoid lockdep warning, -&gt;ndo_get_lock_subclass() was added
to get lockdep subclass value, which is actually lower nested depth value.
But now, they use the dynamic lockdep key to avoid lockdep warning instead
of the subclass.
So, this patch removes -&gt;ndo_get_lock_subclass() callback.

Signed-off-by: Taehee Yoo &lt;ap420073@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net: core: add ignore flag to netdev_adjacent structure</title>
<updated>2019-10-24T21:53:48+00:00</updated>
<author>
<name>Taehee Yoo</name>
<email>ap420073@gmail.com</email>
</author>
<published>2019-10-21T18:47:56+00:00</published>
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<id>urn:sha1:32b6d34fedc2229cdf6a047fdbc0704085441915</id>
<content type='text'>
In order to link an adjacent node, netdev_upper_dev_link() is used
and in order to unlink an adjacent node, netdev_upper_dev_unlink() is used.
unlink operation does not fail, but link operation can fail.

In order to exchange adjacent nodes, we should unlink an old adjacent
node first. then, link a new adjacent node.
If link operation is failed, we should link an old adjacent node again.
But this link operation can fail too.
It eventually breaks the adjacent link relationship.

This patch adds an ignore flag into the netdev_adjacent structure.
If this flag is set, netdev_upper_dev_link() ignores an old adjacent
node for a moment.

This patch also adds new functions for other modules.
netdev_adjacent_change_prepare()
netdev_adjacent_change_commit()
netdev_adjacent_change_abort()

netdev_adjacent_change_prepare() inserts new device into adjacent list
but new device is not allowed to use immediately.
If netdev_adjacent_change_prepare() fails, it internally rollbacks
adjacent list so that we don't need any other action.
netdev_adjacent_change_commit() deletes old device in the adjacent list
and allows new device to use.
netdev_adjacent_change_abort() rollbacks adjacent list.

Signed-off-by: Taehee Yoo &lt;ap420073@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
</feed>
