Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

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diff --git a/Documentation/networking/netdev-FAQ.rst b/Documentation/networking/netdev-FAQ.rst
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+.. SPDX-License-Identifier: GPL-2.0
+
+.. _netdev-FAQ:
+
+==========
+netdev FAQ
+==========
+
+Q: What is netdev?
+------------------
+A: It is a mailing list for all network-related Linux stuff.  This
+includes anything found under net/ (i.e. core code like IPv6) and
+drivers/net (i.e. hardware specific drivers) in the Linux source tree.
+
+Note that some subsystems (e.g. wireless drivers) which have a high
+volume of traffic have their own specific mailing lists.
+
+The netdev list is managed (like many other Linux mailing lists) through
+VGER (http://vger.kernel.org/) and archives can be found below:
+
+-  http://marc.info/?l=linux-netdev
+-  http://www.spinics.net/lists/netdev/
+
+Aside from subsystems like that mentioned above, all network-related
+Linux development (i.e. RFC, review, comments, etc.) takes place on
+netdev.
+
+Q: How do the changes posted to netdev make their way into Linux?
+-----------------------------------------------------------------
+A: There are always two trees (git repositories) in play.  Both are
+driven by David Miller, the main network maintainer.  There is the
+``net`` tree, and the ``net-next`` tree.  As you can probably guess from
+the names, the ``net`` tree is for fixes to existing code already in the
+mainline tree from Linus, and ``net-next`` is where the new code goes
+for the future release.  You can find the trees here:
+
+- https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git
+- https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git
+
+Q: How often do changes from these trees make it to the mainline Linus tree?
+----------------------------------------------------------------------------
+A: To understand this, you need to know a bit of background information on
+the cadence of Linux development.  Each new release starts off with a
+two week "merge window" where the main maintainers feed their new stuff
+to Linus for merging into the mainline tree.  After the two weeks, the
+merge window is closed, and it is called/tagged ``-rc1``.  No new
+features get mainlined after this -- only fixes to the rc1 content are
+expected.  After roughly a week of collecting fixes to the rc1 content,
+rc2 is released.  This repeats on a roughly weekly basis until rc7
+(typically; sometimes rc6 if things are quiet, or rc8 if things are in a
+state of churn), and a week after the last vX.Y-rcN was done, the
+official vX.Y is released.
+
+Relating that to netdev: At the beginning of the 2-week merge window,
+the ``net-next`` tree will be closed - no new changes/features.  The
+accumulated new content of the past ~10 weeks will be passed onto
+mainline/Linus via a pull request for vX.Y -- at the same time, the
+``net`` tree will start accumulating fixes for this pulled content
+relating to vX.Y
+
+An announcement indicating when ``net-next`` has been closed is usually
+sent to netdev, but knowing the above, you can predict that in advance.
+
+IMPORTANT: Do not send new ``net-next`` content to netdev during the
+period during which ``net-next`` tree is closed.
+
+Shortly after the two weeks have passed (and vX.Y-rc1 is released), the
+tree for ``net-next`` reopens to collect content for the next (vX.Y+1)
+release.
+
+If you aren't subscribed to netdev and/or are simply unsure if
+``net-next`` has re-opened yet, simply check the ``net-next`` git
+repository link above for any new networking-related commits.  You may
+also check the following website for the current status:
+
+  http://vger.kernel.org/~davem/net-next.html
+
+The ``net`` tree continues to collect fixes for the vX.Y content, and is
+fed back to Linus at regular (~weekly) intervals.  Meaning that the
+focus for ``net`` is on stabilization and bug fixes.
+
+Finally, the vX.Y gets released, and the whole cycle starts over.
+
+Q: So where are we now in this cycle?
+
+Load the mainline (Linus) page here:
+
+  https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
+
+and note the top of the "tags" section.  If it is rc1, it is early in
+the dev cycle.  If it was tagged rc7 a week ago, then a release is
+probably imminent.
+
+Q: How do I indicate which tree (net vs. net-next) my patch should be in?
+-------------------------------------------------------------------------
+A: Firstly, think whether you have a bug fix or new "next-like" content.
+Then once decided, assuming that you use git, use the prefix flag, i.e.
+::
+
+  git format-patch --subject-prefix='PATCH net-next' start..finish
+
+Use ``net`` instead of ``net-next`` (always lower case) in the above for
+bug-fix ``net`` content.  If you don't use git, then note the only magic
+in the above is just the subject text of the outgoing e-mail, and you
+can manually change it yourself with whatever MUA you are comfortable
+with.
+
+Q: I sent a patch and I'm wondering what happened to it?
+--------------------------------------------------------
+Q: How can I tell whether it got merged?
+A: Start by looking at the main patchworks queue for netdev:
+
+  http://patchwork.ozlabs.org/project/netdev/list/
+
+The "State" field will tell you exactly where things are at with your
+patch.
+
+Q: The above only says "Under Review".  How can I find out more?
+----------------------------------------------------------------
+A: Generally speaking, the patches get triaged quickly (in less than
+48h).  So be patient.  Asking the maintainer for status updates on your
+patch is a good way to ensure your patch is ignored or pushed to the
+bottom of the priority list.
+
+Q: I submitted multiple versions of the patch series
+----------------------------------------------------
+Q: should I directly update patchwork for the previous versions of these
+patch series?
+A: No, please don't interfere with the patch status on patchwork, leave
+it to the maintainer to figure out what is the most recent and current
+version that should be applied. If there is any doubt, the maintainer
+will reply and ask what should be done.
+
+Q: How can I tell what patches are queued up for backporting to the various stable releases?
+--------------------------------------------------------------------------------------------
+A: Normally Greg Kroah-Hartman collects stable commits himself, but for
+networking, Dave collects up patches he deems critical for the
+networking subsystem, and then hands them off to Greg.
+
+There is a patchworks queue that you can see here:
+
+  http://patchwork.ozlabs.org/bundle/davem/stable/?state=*
+
+It contains the patches which Dave has selected, but not yet handed off
+to Greg.  If Greg already has the patch, then it will be here:
+
+  https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git
+
+A quick way to find whether the patch is in this stable-queue is to
+simply clone the repo, and then git grep the mainline commit ID, e.g.
+::
+
+  stable-queue$ git grep -l 284041ef21fdf2e
+  releases/3.0.84/ipv6-fix-possible-crashes-in-ip6_cork_release.patch
+  releases/3.4.51/ipv6-fix-possible-crashes-in-ip6_cork_release.patch
+  releases/3.9.8/ipv6-fix-possible-crashes-in-ip6_cork_release.patch
+  stable/stable-queue$
+
+Q: I see a network patch and I think it should be backported to stable.
+-----------------------------------------------------------------------
+Q: Should I request it via stable@vger.kernel.org like the references in
+the kernel's Documentation/process/stable-kernel-rules.rst file say?
+A: No, not for networking.  Check the stable queues as per above first
+to see if it is already queued.  If not, then send a mail to netdev,
+listing the upstream commit ID and why you think it should be a stable
+candidate.
+
+Before you jump to go do the above, do note that the normal stable rules
+in :ref:`Documentation/process/stable-kernel-rules.rst <stable_kernel_rules>`
+still apply.  So you need to explicitly indicate why it is a critical
+fix and exactly what users are impacted.  In addition, you need to
+convince yourself that you *really* think it has been overlooked,
+vs. having been considered and rejected.
+
+Generally speaking, the longer it has had a chance to "soak" in
+mainline, the better the odds that it is an OK candidate for stable.  So
+scrambling to request a commit be added the day after it appears should
+be avoided.
+
+Q: I have created a network patch and I think it should be backported to stable.
+--------------------------------------------------------------------------------
+Q: Should I add a Cc: stable@vger.kernel.org like the references in the
+kernel's Documentation/ directory say?
+A: No.  See above answer.  In short, if you think it really belongs in
+stable, then ensure you write a decent commit log that describes who
+gets impacted by the bug fix and how it manifests itself, and when the
+bug was introduced.  If you do that properly, then the commit will get
+handled appropriately and most likely get put in the patchworks stable
+queue if it really warrants it.
+
+If you think there is some valid information relating to it being in
+stable that does *not* belong in the commit log, then use the three dash
+marker line as described in
+:ref:`Documentation/process/submitting-patches.rst <the_canonical_patch_format>`
+to temporarily embed that information into the patch that you send.
+
+Q: Are all networking bug fixes backported to all stable releases?
+------------------------------------------------------------------
+A: Due to capacity, Dave could only take care of the backports for the
+last two stable releases. For earlier stable releases, each stable
+branch maintainer is supposed to take care of them. If you find any
+patch is missing from an earlier stable branch, please notify
+stable@vger.kernel.org with either a commit ID or a formal patch
+backported, and CC Dave and other relevant networking developers.
+
+Q: Is the comment style convention different for the networking content?
+------------------------------------------------------------------------
+A: Yes, in a largely trivial way.  Instead of this::
+
+  /*
+   * foobar blah blah blah
+   * another line of text
+   */
+
+it is requested that you make it look like this::
+
+  /* foobar blah blah blah
+   * another line of text
+   */
+
+Q: I am working in existing code that has the former comment style and not the latter.
+--------------------------------------------------------------------------------------
+Q: Should I submit new code in the former style or the latter?
+A: Make it the latter style, so that eventually all code in the domain
+of netdev is of this format.
+
+Q: I found a bug that might have possible security implications or similar.
+---------------------------------------------------------------------------
+Q: Should I mail the main netdev maintainer off-list?**
+A: No. The current netdev maintainer has consistently requested that
+people use the mailing lists and not reach out directly.  If you aren't
+OK with that, then perhaps consider mailing security@kernel.org or
+reading about http://oss-security.openwall.org/wiki/mailing-lists/distros
+as possible alternative mechanisms.
+
+Q: What level of testing is expected before I submit my change?
+---------------------------------------------------------------
+A: If your changes are against ``net-next``, the expectation is that you
+have tested by layering your changes on top of ``net-next``.  Ideally
+you will have done run-time testing specific to your change, but at a
+minimum, your changes should survive an ``allyesconfig`` and an
+``allmodconfig`` build without new warnings or failures.
+
+Q: Any other tips to help ensure my net/net-next patch gets OK'd?
+-----------------------------------------------------------------
+A: Attention to detail.  Re-read your own work as if you were the
+reviewer.  You can start with using ``checkpatch.pl``, perhaps even with
+the ``--strict`` flag.  But do not be mindlessly robotic in doing so.
+If your change is a bug fix, make sure your commit log indicates the
+end-user visible symptom, the underlying reason as to why it happens,
+and then if necessary, explain why the fix proposed is the best way to
+get things done.  Don't mangle whitespace, and as is common, don't
+mis-indent function arguments that span multiple lines.  If it is your
+first patch, mail it to yourself so you can test apply it to an
+unpatched tree to confirm infrastructure didn't mangle it.
+
+Finally, go back and read
+:ref:`Documentation/process/submitting-patches.rst <submittingpatches>`
+to be sure you are not repeating some common mistake documented there.