.. _stable_kernel_rules:

  Everything you ever wanted to know about Linux -stable releases
  ===============================================================

  Rules on what kind of patches are accepted, and which ones are not, into the
  "-stable" tree:

  
   - It must be obviously correct and tested.

   - It cannot be bigger than 100 lines, with context.

   - It must fix only one thing.
   - It must fix a real bug that bothers people (not a, "This could be a

     problem..." type thing).

   - It must fix a problem that causes a build error (but not for things
     marked CONFIG_BROKEN), an oops, a hang, data corruption, a real

     security issue, or some "oh, that's not good" issue.  In short, something
     critical.

   - Serious issues as reported by a user of a distribution kernel may also
     be considered if they fix a notable performance or interactivity issue.
     As these fixes are not as obvious and have a higher risk of a subtle
     regression they should only be submitted by a distribution kernel
     maintainer and include an addendum linking to a bugzilla entry if it
     exists and additional information on the user-visible impact.

   - New device IDs and quirks are also accepted.

   - No "theoretical race condition" issues, unless an explanation of how the
     race can be exploited is also provided.

   - It cannot contain any "trivial" fixes in it (spelling changes,

     whitespace cleanups, etc).

   - It must follow the
     :ref:`Documentation/SubmittingPatches <submittingpatches>`
     rules.

   - It or an equivalent fix must already exist in Linus' tree (upstream).

  Procedure for submitting patches to the -stable tree
  ----------------------------------------------------

   - If the patch covers files in net/ or drivers/net please follow netdev stable
     submission guidelines as described in
     Documentation/networking/netdev-FAQ.txt

   - Security patches should not be handled (solely) by the -stable review

     process but should follow the procedures in
     :ref:`Documentation/SecurityBugs <securitybugs>`.

  For all other submissions, choose one of the following procedures
  -----------------------------------------------------------------

  .. _option_1:
  
  Option 1
  ********
  
  To have the patch automatically included in the stable tree, add the tag
  
  .. code-block:: none

       Cc: stable@vger.kernel.org

  in the sign-off area. Once the patch is merged it will be applied to
  the stable tree without anything else needing to be done by the author
  or subsystem maintainer.
  
  .. _option_2:

  Option 2
  ********

  After the patch has been merged to Linus' tree, send an email to
  stable@vger.kernel.org containing the subject of the patch, the commit ID,
  why you think it should be applied, and what kernel version you wish it to
  be applied to.

  .. _option_3:

  Option 3
  ********

  Send the patch, after verifying that it follows the above rules, to
  stable@vger.kernel.org.  You must note the upstream commit ID in the
  changelog of your submission, as well as the kernel version you wish
  it to be applied to.
  
  :ref:`option_1` is **strongly** preferred, is the easiest and most common.
  :ref:`option_2` and :ref:`option_3` are more useful if the patch isn't deemed
  worthy at the time it is applied to a public git tree (for instance, because
  it deserves more regression testing first).  :ref:`option_3` is especially
  useful if the patch needs some special handling to apply to an older kernel
  (e.g., if API's have changed in the meantime).
  
  Note that for :ref:`option_3`, if the patch deviates from the original
  upstream patch (for example because it had to be backported) this must be very
  clearly documented and justified in the patch description.

  
  The upstream commit ID must be specified with a separate line above the commit
  text, like this:

  .. code-block:: none

      commit <sha1> upstream.

  
  Additionally, some patches submitted via Option 1 may have additional patch
  prerequisites which can be cherry-picked. This can be specified in the following
  format in the sign-off area:

  .. code-block:: none

       Cc: <stable@vger.kernel.org> # 3.3.x: a1f84a3: sched: Check for idle
       Cc: <stable@vger.kernel.org> # 3.3.x: 1b9508f: sched: Rate-limit newidle
       Cc: <stable@vger.kernel.org> # 3.3.x: fd21073: sched: Fix affinity logic
       Cc: <stable@vger.kernel.org> # 3.3.x

       Signed-off-by: Ingo Molnar <mingo@elte.hu>
  
  The tag sequence has the meaning of:
  
  .. code-block:: none

       git cherry-pick a1f84a3
       git cherry-pick 1b9508f
       git cherry-pick fd21073
       git cherry-pick <this commit>

  Also, some patches may have kernel version prerequisites.  This can be
  specified in the following format in the sign-off area:

  .. code-block:: none

       Cc: <stable@vger.kernel.org> # 3.3.x-

  The tag has the meaning of:
  
  .. code-block:: none

       git cherry-pick <this commit>

  For each "-stable" tree starting with the specified version.

  Following the submission:

   - The sender will receive an ACK when the patch has been accepted into the
     queue, or a NAK if the patch is rejected.  This response might take a few
     days, according to the developer's schedules.
   - If accepted, the patch will be added to the -stable queue, for review by

     other developers and by the relevant subsystem maintainer.

  Review cycle
  ------------

   - When the -stable maintainers decide for a review cycle, the patches will be
     sent to the review committee, and the maintainer of the affected area of
     the patch (unless the submitter is the maintainer of the area) and CC: to
     the linux-kernel mailing list.
   - The review committee has 48 hours in which to ACK or NAK the patch.

   - If the patch is rejected by a member of the committee, or linux-kernel

     members object to the patch, bringing up issues that the maintainers and
     members did not realize, the patch will be dropped from the queue.
   - At the end of the review cycle, the ACKed patches will be added to the
     latest -stable release, and a new -stable release will happen.
   - Security patches will be accepted into the -stable tree directly from the
     security kernel team, and not go through the normal review cycle.

     Contact the kernel security team for more details on this procedure.

  Trees
  -----

  
   - The queues of patches, for both completed versions and in progress
     versions can be found at:

  	http://git.kernel.org/?p=linux/kernel/git/stable/stable-queue.git

   - The finalized and tagged releases of all stable kernels can be found
     in separate branches per version at:

  	http://git.kernel.org/?p=linux/kernel/git/stable/linux-stable.git

  Review committee
  ----------------

   - This is made up of a number of kernel developers who have volunteered for
     this task, and a few that haven't.