1.. _submitchecklist:
  2
  3Linux Kernel patch submission checklist
  4~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  5
  6Here are some basic things that developers should do if they want to see their
  7kernel patch submissions accepted more quickly.
  8
  9These are all above and beyond the documentation that is provided in
 10:ref:`Documentation/process/submitting-patches.rst <submittingpatches>`
 11and elsewhere regarding submitting Linux kernel patches.
 12
 13
 141) If you use a facility then #include the file that defines/declares
 15   that facility.  Don't depend on other header files pulling in ones
 16   that you use.
 17
 182) Builds cleanly:
 19
 20  a) with applicable or modified ``CONFIG`` options ``=y``, ``=m``, and
 21     ``=n``.  No ``gcc`` warnings/errors, no linker warnings/errors.
 22
 23  b) Passes ``allnoconfig``, ``allmodconfig``
 24
 25  c) Builds successfully when using ``O=builddir``
 26
 273) Builds on multiple CPU architectures by using local cross-compile tools
 28   or some other build farm.
 29
 304) ppc64 is a good architecture for cross-compilation checking because it
 31   tends to use ``unsigned long`` for 64-bit quantities.
 32
 335) Check your patch for general style as detailed in
 34   :ref:`Documentation/process/coding-style.rst <codingstyle>`.
 35   Check for trivial violations with the patch style checker prior to
 36   submission (``scripts/checkpatch.pl``).
 37   You should be able to justify all violations that remain in
 38   your patch.
 39
 406) Any new or modified ``CONFIG`` options do not muck up the config menu and
 41   default to off unless they meet the exception criteria documented in
 42   ``Documentation/kbuild/kconfig-language.txt`` Menu attributes: default value.
 43
 447) All new ``Kconfig`` options have help text.
 45
 468) Has been carefully reviewed with respect to relevant ``Kconfig``
 47   combinations.  This is very hard to get right with testing -- brainpower
 48   pays off here.
 49
 509) Check cleanly with sparse.
 51
 5210) Use ``make checkstack`` and ``make namespacecheck`` and fix any problems
 53    that they find.
 54
 55    .. note::
 56
 57       ``checkstack`` does not point out problems explicitly,
 58       but any one function that uses more than 512 bytes on the stack is a
 59       candidate for change.
 60
 6111) Include :ref:`kernel-doc <kernel_doc>` to document global  kernel APIs.
 62    (Not required for static functions, but OK there also.) Use
 63    ``make htmldocs`` or ``make pdfdocs`` to check the
 64    :ref:`kernel-doc <kernel_doc>` and fix any issues.
 65
 6612) Has been tested with ``CONFIG_PREEMPT``, ``CONFIG_DEBUG_PREEMPT``,
 67    ``CONFIG_DEBUG_SLAB``, ``CONFIG_DEBUG_PAGEALLOC``, ``CONFIG_DEBUG_MUTEXES``,
 68    ``CONFIG_DEBUG_SPINLOCK``, ``CONFIG_DEBUG_ATOMIC_SLEEP``,
 69    ``CONFIG_PROVE_RCU`` and ``CONFIG_DEBUG_OBJECTS_RCU_HEAD`` all
 70    simultaneously enabled.
 71
 7213) Has been build- and runtime tested with and without ``CONFIG_SMP`` and
 73    ``CONFIG_PREEMPT.``
 74
 7514) If the patch affects IO/Disk, etc: has been tested with and without
 76    ``CONFIG_LBDAF.``
 77
 7815) All codepaths have been exercised with all lockdep features enabled.
 79
 8016) All new ``/proc`` entries are documented under ``Documentation/``
 81
 8217) All new kernel boot parameters are documented in
 83    ``Documentation/admin-guide/kernel-parameters.rst``.
 84
 8518) All new module parameters are documented with ``MODULE_PARM_DESC()``
 86
 8719) All new userspace interfaces are documented in ``Documentation/ABI/``.
 88    See ``Documentation/ABI/README`` for more information.
 89    Patches that change userspace interfaces should be CCed to
 90    linux-api@vger.kernel.org.
 91
 9220) Check that it all passes ``make headers_check``.
 93
 9421) Has been checked with injection of at least slab and page-allocation
 95    failures.  See ``Documentation/fault-injection/``.
 96
 97    If the new code is substantial, addition of subsystem-specific fault
 98    injection might be appropriate.
 99
10022) Newly-added code has been compiled with ``gcc -W`` (use
101    ``make EXTRA_CFLAGS=-W``).  This will generate lots of noise, but is good
102    for finding bugs like "warning: comparison between signed and unsigned".
103
10423) Tested after it has been merged into the -mm patchset to make sure
105    that it still works with all of the other queued patches and various
106    changes in the VM, VFS, and other subsystems.
107
10824) All memory barriers {e.g., ``barrier()``, ``rmb()``, ``wmb()``} need a
109    comment in the source code that explains the logic of what they are doing
110    and why.
111
11225) If any ioctl's are added by the patch, then also update
113    ``Documentation/ioctl/ioctl-number.txt``.
114
11526) If your modified source code depends on or uses any of the kernel
116    APIs or features that are related to the following ``Kconfig`` symbols,
117    then test multiple builds with the related ``Kconfig`` symbols disabled
118    and/or ``=m`` (if that option is available) [not all of these at the
119    same time, just various/random combinations of them]:
120
121    ``CONFIG_SMP``, ``CONFIG_SYSFS``, ``CONFIG_PROC_FS``, ``CONFIG_INPUT``, ``CONFIG_PCI``, ``CONFIG_BLOCK``, ``CONFIG_PM``, ``CONFIG_MAGIC_SYSRQ``,
122    ``CONFIG_NET``, ``CONFIG_INET=n`` (but latter with ``CONFIG_NET=y``).