Linux kernel source tree for SHARP Brain series (PW-SH1 or later)
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Jon Maloy e654f9f53b tipc: clean up skb list lock handling on send path
The policy for handling the skb list locks on the send and receive paths
is simple.

- On the send path we never need to grab the lock on the 'xmitq' list
  when the destination is an exernal node.

- On the receive path we always need to grab the lock on the 'inputq'
  list, irrespective of source node.

However, when transmitting node local messages those will eventually
end up on the receive path of a local socket, meaning that the argument
'xmitq' in tipc_node_xmit() will become the 'ínputq' argument in  the
function tipc_sk_rcv(). This has been handled by always initializing
the spinlock of the 'xmitq' list at message creation, just in case it
may end up on the receive path later, and despite knowing that the lock
in most cases never will be used.

This approach is inaccurate and confusing, and has also concealed the
fact that the stated 'no lock grabbing' policy for the send path is
violated in some cases.

We now clean up this by never initializing the lock at message creation,
instead doing this at the moment we find that the message actually will
enter the receive path. At the same time we fix the four locations
where we incorrectly access the spinlock on the send/error path.

This patch also reverts commit d12cffe932 ("tipc: ensure head->lock
is initialised") which has now become redundant.

CC: Eric Dumazet <edumazet@google.com>
Reported-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-18 14:01:07 -07:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-08-06 18:44:57 -07:00
block for-linus-20190726-2 2019-07-26 19:20:34 -07:00
certs Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
crypto USB / PHY patches for 5.3-rc1 2019-07-11 15:40:06 -07:00
Documentation Documentation: Add a section for devlink-trap testing 2019-08-17 12:40:09 -07:00
drivers net: hns3: add phy_attached_info() to the hns3 driver 2019-08-18 12:59:13 -07:00
fs Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-08-06 17:11:59 -07:00
include Documentation: Add devlink-trap documentation 2019-08-17 12:40:08 -07:00
init Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
ipc Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2019-08-13 16:24:57 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-08-06 17:11:59 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm memremap: move from kernel/ to mm/ 2019-08-03 07:02:01 -07:00
net tipc: clean up skb list lock handling on send path 2019-08-18 14:01:07 -07:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2019-08-13 16:24:57 -07:00
scripts Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2019-08-13 16:24:57 -07:00
security selinux/stable-5.3 PR 20190801 2019-08-02 18:40:49 -07:00
sound sound fixes for 5.3-rc3 2019-08-02 08:53:34 -07:00
tools selftests: devlink_trap: Add test cases for devlink-trap 2019-08-17 12:40:09 -07:00
usr kbuild: enable arch/s390/include/uapi/asm/zcrypt.h for uapi header test 2019-07-23 10:45:46 +02:00
virt Documentation: move Documentation/virtual to Documentation/virt 2019-07-24 10:52:11 +02:00
.clang-format Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-04-17 11:26:25 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore .gitignore: Add compilation database file 2019-07-27 12:18:19 +09:00
.mailmap MAINTAINERS: Update my email address 2019-07-22 14:57:50 +01:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS Remove references to dead website. 2019-07-19 12:22:04 -07:00
Kbuild Kbuild updates for v5.1 2019-03-10 17:48:21 -07:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS drop_monitor: Add basic infrastructure for hardware drops 2019-08-17 12:40:08 -07:00
Makefile Linux 5.3-rc3 2019-08-04 18:40:12 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.